ARES are a well known brand in the Asia market today due to their affordable AEG and sniper rifles. They've been making airsoft guns for awhile and know what the market wants when it comes to affordable yet quality cost guns. 

The C.P.S.B. Upgrade Spring is part of a series of spring they've released which is designed only for the ARES Amoeba Striker system, so please refrain from installing into other platforms.