AirGhandi's Accessory Guide for the Huben GK1 and Huben K1

The Huben GK1 and the Huben K1 are among the most widely discussed semi-automatic PCP airguns on the market. Anyone who owns one of these two guns – or is thinking about getting one – will sooner or later ask the same question: which accessories actually make sense? AirGhandi from jabolo.de has spent considerable time with both platforms and presents here the accessory solutions available at jabolo.de that can be meaningfully used in practice.

Huben K1 and Huben GK1 – two exceptional PCP airguns

The Huben K1 is a semi-automatic PCP rifle in a bullpup design, calibre 5.5 mm. It operates on a hammerless principle – no manual cocking is required between shots. A fixed 19-round drum magazine enables a rapid rate of fire. Despite its long barrel, the bullpup design keeps the gun comparatively compact.

The Huben GK1 transfers the same concept into a pistol format: semi-automatic, hammerless, calibre 5.5 mm, also with a fixed 19-round drum magazine. The GK1's particular strength lies in its modularity. Depending on the chosen accessories, the compact pistol can be transformed into a completely different setup: fitted with a reflex sight, additional Picatinny rails, or extended into a carbine configuration with a shoulder stock.

AirGhandi's Optic Recommendation: Anschütz Optics Reflex Pro wide (28x20)

For those seeking fast target acquisition on the Huben GK1 or a similarly configured K1, AirGhandi considers the Anschütz Optics Reflex Pro wide (28x20) a well-suited option. The reflex sight features a particularly large field of view (28 x 20 mm objective lens), requires no magnification, and does not demand precise eye positioning behind the optic.

Technical specifications according to the manufacturer:

• Magnification: 1.0x
• Objective lens: 28 x 20 mm
• 3 reticles: dot, circle, circle with dot
• Dot size: 2 MOA; circle: 35 MOA
• Click value: 1/2 MOA; adjustment range: 100 MOA
• 7 brightness levels, automatic activation by movement
• Waterproof to IP67
• Weight: 42 g; length: 46 mm
• Rail: Picatinny/Weaver; RMR footprint
• Battery type: CR1632

The low weight of 42 g is, according to the product description, a key advantage for compact setups. Additionally, Anschütz Optics is currently running a cashback promotion: after purchasing at jabolo.de, the invoice can be uploaded to Anschütz Optics to receive 10% of the purchase price back. Terms and conditions of ahg Anschütz Handels GmbH apply.

Picatinny Rails for the Huben GK1 – Short or Long

To mount an optic such as the Anschütz Reflex Pro, a suitable Picatinny rail is required. jabolo.de offers two versions for the Huben GK1:

Short Picatinny Rail

The Picatinny rail - short version | CNC ALU | black anodized | Huben GK1 is CNC-machined from aluminium, black anodized, and provides a 21 mm Picatinny mount. Dimensions are approximately 60 x 22 mm (L x W). Important: This rail is exclusively compatible with the German GK1 model with two-point attachment. The iron sights remain fully usable after installation.

Long Picatinny Rail

Those needing more mounting surface or greater flexibility in optic positioning can opt for the Long Picatinny Alu Rail – Huben GK1 Universal & Mini Pro - 21 mm. The rail slides onto the existing 11 mm prism rail and is secured via the rear sight – no removal of the rear sight is necessary. It is suitable for all calibres and compatible with the Huben GK1 and the Huben MINI PRO.

Bottle Clamp – Additional Picatinny Mounts on the Bottle

Those looking for even more mounting options will find the BOTTLE CLAMP | Huben GK1 | 3x Picatinny a practical addition. The clamp attaches to the GK1's air bottle and offers three additional Picatinny rails. It is 3D-printed from plastic, keeps weight low, and is delivered with an anti-slip band to ensure a secure fit. The gun is not permanently modified.

Lower Picatinny Rail Kit | Triggerguard | Huben GK1 V3 – Rail on the Trigger Guard

For the Huben GK1 V3, the Lower Picatinny Rail Kit | Triggerguard | Huben GK1 V3 provides a further mounting option. The original trigger guard is replaced by an aluminium version with an integrated Picatinny rail on the underside. The installation requires neither drilling nor thread-cutting and can, according to the manufacturer, be fully reversed at any time.

Legal notice: According to the jabolo.de product description, removing the original trigger guard may result in the loss of the power limitation. Before installation, the applicable legal regulations of the respective country must be checked carefully.

Safety Lever – Ergonomic Upgrade for the Safety

The SAFETY LEVER | Enlarged Lever | Huben GK1 replaces the original safety lever with an enlarged version made from black anodized aluminium. According to the product description, the larger design improves accessibility and operability compared to the original part. Installation is plug-and-play with no further modifications required. Compatible with the Huben GK1 and GK1 Mini Pro (Shorty). Included in delivery: 1x lever, 1x screw.

AirGhandi's Recommendation: Deluxe Loading Gate for the Huben GK1 V3

The Deluxe Loading Gate for Huben GK1 V3 – Cal.22 / 5.5 mm – Black is an upgrade component that replaces the original loading gate of the Huben GK1 V3 in calibre .22 / 5.5 mm. It is CNC-machined from aluminium, black anodized, and features, according to the manufacturer, a precise fit and an integrated O-ring for smooth opening and closing. Important: This part is exclusively designed for the GK1 V3 in calibre .22 / 5.5 mm – verify model and calibre before ordering.

The Huben GK1 as a Carbine – Buttstock Adapter and Shoulder Rest

One of the most significant conversion options is extending the GK1 into a carbine setup. This first requires the Huben GK1 Buttstock Adapter - Optional for a carbine configuration - black. The adapter is CNC-machined from aluminium, black anodized, and designed for the Huben GK1 EU version. Installation does not require removal of the rear sight. An attachment point for an optional sling is also integrated.

The Huben GK1 Shoulder Rest | black anodized aluminum | foldable | for additional Picatinny rails can then be mounted onto this adapter. The shoulder rest is CNC-machined from aluminium (black anodized), weighs approximately 280 g, and measures approximately 200 x 100 mm (L x H). An integrated folding mechanism allows the rest to be folded sideways for more compact transport. Additional Picatinny accessories can also be attached to the shoulder rest.

Note: According to the product description, the shoulder rest can only be used in combination with the Saber Tactical buttstock adapter (item no. 303145, sold separately). Compatibility of individual components should be verified before ordering. When carrying out any such conversion, the applicable legal regulations must always be observed.

Holster for the Huben GK1 – for Training and the Shooting Range

Those who use the GK1 deliberately as a pistol will find the HOLSTER for Huben GK1 | Air Pistol Holster | incl. two belt clips a purpose-made carrying solution. The holster is made from PetG-CF (carbon fibre reinforced plastic) and is precisely fitted to the shape of the Huben GK1. It is available as a right-handed version and is delivered with two different belt clips:

• Closed belt clip – for a particularly secure and firm fit
• Open belt clip – for quick attachment and removal

Suppressor Adapters and Moderators for the GK1 and K1

To mount a suppressor on the Huben GK1, the DonnyFL Huben GK1 Moderator Adapter is required first. This enables the use of suppressors with a 1/2 x 20 thread. The adapter is made from 6061 T6 aluminium and is black anodized. It is compatible with the Huben GK1 and the Huben GK1 Mini Pro (Shorty).

For the Huben K1, the DonnyFL Huben K1 1/2 x 20 Adapter A9 is available. Important: According to the product description, this adapter is not compatible with the first generation of the Huben K1. The exact K1 version should be checked before ordering.

Once the appropriate adapter is fitted, various suppressors can be used. jabolo.de stocks two DonnyFL variants, among others:

DonnyFL RYU QD – precision-machined moderator with quick-detach system

The DonnyFL RYU QD Silencer 6,35mm /.25 - 1/2x20 features an indexed quick-detach (QD) locking system which, according to the manufacturer, ensures a consistent position and no point-of-impact shift after removal and reattachment. Made from 6061 T6 aluminium (sections) and 7075 aluminium (main housing and adapter). Modular design for length adjustment. Thread: 1/2" UNF; calibre: .22 (5.5 mm), .25 (6.35 mm).

DonnyFL YOKOZUNA QD – larger version for increased moderation volume

The DonnyFL YOKOZUNA QD Silencer 6,35mm /.25 - 1/2x20 shares the same QD technology and material construction as the RYU, but has a larger outer diameter (40.46 mm according to the manufacturer). It also features a modular design. Thread: 1/2" UNF; calibre: .22 (5.5 mm), .25 (6.35 mm). Note: the latest version is delivered with an adjustable QD system and included tool.

Important note on calibre selection: According to the DonnyFL product description, the suppressor should be selected in the next larger calibre if the adapter cannot be screwed directly onto the barrel but must instead be mounted on a barrel shroud.

Spare Part: Huben GK1 Trigger Assembly

For guns that are used regularly and intensively, it is reassuring to know that spare parts are available. The Huben GK1 Trigger Assembly is available at jabolo.de as a complete replacement part and includes the trigger guard with pre-mounted trigger. It is compatible with the Huben GK1 and the Huben GK1 Mini Pro. This means that a damaged or worn component does not necessarily require replacing the entire gun.

Check Compatibility – Different GK1 and K1 Versions

Both the Huben GK1 and the Huben K1 exist in several generations and versions. Not every accessory is automatically compatible with every variant. Before ordering, it should always be confirmed that the chosen product is compatible with the specific gun version. Compatibility information is listed on the relevant product pages at jabolo.de. If in doubt, the jabolo.de customer service team can be contacted for advice.

Order Accessories for the Huben GK1 and K1 at jabolo.de Now

jabolo.de has specialised in airgun accessories for many years. The range includes optics, suppressors, adapters, mounts, and precision CNC-machined components. All products presented here are available at jabolo.de:

• Anschütz Optics Reflex Pro wide (28x20)
• Picatinny rail - short version | CNC ALU | black anodized | Huben GK1
• Long Picatinny Alu Rail – Huben GK1 Universal & Mini Pro - 21 mm
• BOTTLE CLAMP | Huben GK1 | 3x Picatinny
• Lower Picatinny Rail Kit | Triggerguard | Huben GK1 V3
• SAFETY LEVER | Enlarged Lever | Huben GK1
• Deluxe Loading Gate for Huben GK1 V3 – Cal.22 / 5.5 mm – Black
• Huben GK1 Buttstock Adapter - Optional for a carbine configuration - black
• Huben GK1 Shoulder Rest | black anodized aluminum | foldable | for additional Picatinny rails
• HOLSTER for Huben GK1 | Air Pistol Holster | incl. two belt clips
• DonnyFL Huben GK1 Moderator Adapter
• DonnyFL Huben K1 1/2 x 20 Adapter A9
• DonnyFL RYU QD Silencer 6,35mm /.25 - 1/2x20
• DonnyFL YOKOZUNA QD Silencer 6,35mm /.25 - 1/2x20
• Huben GK1 Trigger Assembly

Who is AirGhandi?

AirGhandi is co-founder of jabolo GmbH and has been a content creator in the air rifle space for over 10 years. He has worked with nearly all major air rifle brands, tested more than 200 air rifles, and published over 600 videos.

Notice: Please inform yourself about the applicable weapons laws in your country before purchasing. The purchase, possession and use of air guns and accessories are subject to country-specific regulations. jabolo.de exclusively sells products that are legally available in Germany.