Hakkotsu Thunder B CO2 Sound Effect Airsoft / Paintball Simulation Grenade Core Hi-Cap Magazines the HK UMP GBB is

the HK UMP GBB is part of our Elite Series of products and earns its keep in our flagship line with a high-strength polymer body

NXL full-automatic

AKA Adjustable LPR installed

Screen Standby Time

This is a very well made unit

Hakkotsu Thunder B CO2 Sound Effect Airsoft / Paintball Simulation Grenade Core Hi-Cap Magazines the HK UMP GBB isA Thunder B is an Airsoft simulation grenade that emits noise. It holds a standard 12 gram CO2 cartridge in a fully sealed compartment. Upon pulling the pin, the fire lever, or spoon, snaps down puncturing the CO2 cartridge and starts releasing the pressure from the cartridge until the shell breaks due to air pressure inside the shell resulting in a loud pop sound. The Thunder B Spare Core is perfect as a replacement set and also allows you to have