KJ Works KP-17 23rds CO2 Magazine For KP-13/17/18 GBB
 
Remove base cap to insert CO2 cartridge
KJ WORKS G Series, Including KP-13, KP-17, KP-18 
Capactity: 23+1 6MM BB
Compatitable with Tokyo Marui G Series And Marui Cloned like WE, ARMY..etc
KJ WORKS :MAG-035-KP-18