No—ordinary unthreaded 12g CO₂ capsules are not compatible with the Z-RAM EX25 valve used in an Umarex HDR50/TR50 build. The EX25 uses threaded CO₂ capsules; the current product description names 16g, 20g and 25g.
The capsule interface is the deciding difference
“12g” describes the capsule’s capacity, while “threaded” describes a different part of its identity: the connection. The EX25’s threaded-capsule requirement is not satisfied simply because a cartridge contains CO₂ or was used in an HDR50/TR50 before.
The EX25 valve is made from solid steel and has an integrated Z-Extension. Its current description lists compatible ZDR50v2 and Tec9 body-kit housings, and explicitly excludes the stock Umarex HDR50/TR50 housing because of the valve’s extended shape.
What the ZDR50v2 body purchase gives you
The ZDR50v2 body kit is a separate housing offer, not an EX25 valve or a complete marker. Its listed contents are the two-part body, a drum, a handle and ten screws. The EX25 valve and the required HDR50 internals remain separate.
The ZDR50v2 should not be confused with the earlier ZDR50 case. A familiar exterior or the shared HDR50/TR50 base does not tell you which capsule interface is inside.
And the HPA option?
The EX25 description also names HPA builds. That is a separate supply arrangement; it does not make unthreaded CO₂ cartridges compatible with this valve.
If keeping the original internals is your priority instead, see the separate Tec9 Compact guide for original HDR50/TR50 internals. For an EX25 purchase, match the threaded capsule type and the exact supported body offer before ordering.
The valve and its separate ZDR50v2 housing

Z-RAM EX25-Valve Steel Valve – with Integrated Z-Extension for Tec9 Bodykit or ZDR50v2 (HDR50 / TR50) (22 Jo. 25g, 20g, 16g co2)
The solid-steel EX25 valve with integrated Z-Extension, listed for threaded 16g, 20g and 25g CO₂ capsules and the named ZDR50v2/Tec9 body routes.
View the EX25 valve
Z-RAM ZDR50v2 Body Kit Black, (for EX25-Valve & HDR50 TR50 inerts)
The black ZDR50v2 body kit with drum, handle and screws. It requires the separate EX25 valve and the specified HDR50 internals.
View the body kitThe EX25 and its threaded capsule types
This Z-RAM short identifies the EX25’s threaded 16g, 20g and 25g capsule types and the named body-kit families. It gives a direct product overview for the capsule choice discussed above.
▶ Play on YouTubewww.z-ram.net EX25 Valve for #umarex #Hdr50 #Tr50 #airgun #homedefense #umarexairguns #airsoft
Channel: Z-RAM
Recognizing the separate ZDR50v2 case
This short introduces the ZDR50v2 case alongside the earlier ZDR50 case. It complements the housing-name distinction; the current body and valve descriptions provide the exact purchase requirements.
▶ Play on YouTubeIntroducing the ZDR50v2 Case: The Ultimate Upgrade for Your HDR50 TR50 Umarex
Channel: Z-RAM
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.
