Yes, almost all gas blowback airsoftgun made by KSC/KWA use same exact hop up rubber, including pistols models, some SMG and early version of gas blowback rifle.
The one that use different hopup rubber are:
– VZ 61
– AK models
– Kriss Vector
– New version (KWA LM4) / KSC M4.
This hop up rubber didn’t use tiny ball bearing like other.
As far as i know these 4 models use new model of hop up rubber