Umarex T4E HDC68/TC68 HPA Adapter Kit: 50 mm Bottle Fit

What the kit includes

The package combines the HDC68/TC68 marker-side threaded adapter with a polymer shoulder stock and its bottle holder. The product record lists an assembled length of 27 cm and a listed weight of 635 g. No HPA bottle is included.

The 5 cm measurement applies to the outside diameter of the bottle where the holder grips it. A 0.2 L bottle can be one suitable format, but capacity alone does not prove fit. Another HPA bottle with the same exact 5 cm outer diameter can fit the holder when its remaining technical requirements are also satisfied.

Two compatibility questions, not one

First confirm the marker-side interface: the adapter is for the Umarex T4E HDC68/TC68. Then confirm the bottle-side arrangement: measure the actual bottle outer diameter and require exactly 5 cm at the clamping position. A bottle fitting the stock does not make the marker-side adapter compatible with another marker family.

Keep model families separate. The HDC68/TC68 statement must not be transferred to HDB68/TB68, HDX68/TX68 or another platform merely because it uses HPA or shares the .68 caliber.

What must be checked separately

• Confirm the exact HDC68/TC68 marker-side connection.
• Measure the bottle outside diameter at the holder and require exactly 5 cm.
• Check the bottle pressure rating, regulator output and connection against every component manufacturer's current requirements.
• Inspect threads, seals, alignment and component condition before assembly.
• Keep the marker unloaded and the air system depressurized while checking the fit.

These checks prevent two common buying errors: treating “0.2 L” as the only compatible bottle size, or treating a matching bottle diameter as proof that the adapter fits an unrelated marker.

How to plan the complete HPA system

Plan the adapter, stock, bottle, regulator and filling method as one system while verifying each interface separately. The adapter and stock solve the named marker-side and 5 cm holder requirements; they do not establish a pressure setting, a shot count or a Joule result. Those outcomes depend on the approved components and the complete configuration.

For a broader method, use the Z-RAM parts compatibility guide to separate platform fit, connection fit and operating limits before purchase.

The purchase decision

Choose this kit when you have the named HDC68/TC68 platform and an HPA bottle with an exact 5 cm outer diameter that also passes the pressure, regulator and connection checks. Do not reject or approve a bottle from its volume label alone, and remember that the bottle itself is a separate purchase.

Confirm the exact scope

The marker-side adapter and the bottle-side holder solve different interfaces. Confirming one does not prove the other: the threaded adapter must match HDC68/TC68, while the holder must grip the actual bottle at a measured 5 cm outside diameter.

A 0.2 L bottle may be one workable example when it has the required diameter, but capacity is not the governing measurement. Other capacities are not automatically approved or rejected; their physical diameter and complete technical requirements decide.

Build the decision in the right order

Measure the bottle where the holder clamps, not at a rounded shoulder or protective cover. Then verify the bottle's current ratings, regulator output and connection path against each component's documentation before treating the system as complete.

Use the product's listed contents as the purchase boundary. The adapter and stock cannot be described as including a bottle, regulator or fill equipment when those parts are not listed.

• Confirm HDC68/TC68 marker thread
• Measure exactly 5 cm bottle diameter
• Verify regulator and pressure rating
• List every non-included connection

Avoid the common wrong assumption

The earlier shortcut '0.2 L bottle only' is wrong because volume does not determine clamp diameter. The corrected rule is exact outside diameter, with the rest of the air system checked independently.

A 5 cm bottle does not make this adapter universal across other markers. HDB68/TB68, HDX68/TX68 and other families need their own marker-side compatibility evidence.

Choose the next useful step

Choose the kit when both gates pass: HDC68/TC68 on the marker side and 5 cm at the bottle holder. Build a separate list for bottle, regulator, fill method and connectors before buying any additional air component.

Keep performance expectations outside the fit decision. A physically complete HPA route does not by itself prove a pressure setting, shot count or Joule result.

Continue with the matching Z-RAM guide

For a different external air path, compare the Umarex T4E remote-line adapter planning guide

Use the interface-by-interface compatibility method