A review by Bruce ofBB2K Airsoftof the only gas blowback SIG 553 in the airsoft market made by GHK Airsoft... "The Sig Sauer SG553 is the compact version of the SIG 550 (#Stgw90) or SIG 551 and since 2008 the successor of the SG552 . The long barrel version (SG 553 LB) is ...