The BLOP-STC3 is a power supply that operates with select Mountz electric screwdrivers. It is single tool controller with a built-in screw counter. The quality control device provides visual assembly fastener count and audible reject alarm. Detects - cross threading, omissions, unfinished rundowns and cycle complete. Note: Operates with Electric Screwdriver Models: BL2000-OPC BL7000-OPC and BLG4000-OPC - BLG5000-OPC.Model:BLOP-STC3Tool Weight:4 lbs.Tool Length:8.125Tool Width:5Tool Height:3Maximum Output:4.5AOutput VDC:20/31VInput VAC:100-240VFuse Size:3A