The Speedotron Variable Focus Zoom Spot is compatible with the Speedotron 102 and 103 flash heads.This zoom spot features 4 built-in shutter blades and the pattern holder can accommodate optional standard sized patternsAt a distance of 10', the Speedotron Variable Focus Zoom Spot offers 52" circle of lightIt works with a 2400 w/s power pack, and it weighs about 18 lbs excluding the flash heads