JG Spets Beta (top), Spets Beta F (middle) & Spets Beta full butt (bottom)

-- metal parts like the CYMAs
-- brass barrel
-- adjustable hop up

the buttless spets is being marketed as a Krinkov which is a misrepresentation. the F model first made its appearance in the US. good buys overall, imo -- good power, good build, good durability. some say JG springs do not retain their rating for long

source: gunner airsoft