The marker-side adapter in this Z-RAM kit is intended for the Umarex T4E HDC68/TC68. Its stock holds HPA bottles by an exact 5 cm outer diameter, not by a single bottle volume. The bottle is not included, and the marker connection and bottle-holder fit remain two separate compatibility checks.
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.
View the exact HDC68/TC68 kit
Umarex T4E HPA Adapter Kit for HDC68 TC68 MagFed Marker
Why it belongs: The exact kit contains the marker-side threaded adapter and stock described in this guide.
Decision boundary: The 0.2 L HPA bottle and regulated air supply are not included and require separate rating checks.
View the TC68 HPA Adapter KitWhat 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.
Important Legal Notice
Laws and regulations governing the purchase, possession, installation, modification, and use of the products described on this page vary by country, state, and local jurisdiction and may change. Before purchasing, installing, modifying, or using any product, you are responsible for confirming that it is permitted in your location and for your intended purpose. Product availability or delivery does not mean that purchase, possession, installation, modification, or use is lawful in your jurisdiction. Z-RAM does not provide legal advice, and the information on this page must not be treated as legal advice. If you are unsure, contact the competent local authority or a qualified legal professional.