Reed's DH81-4 is a Enclosed Ratchet Threaded Set. It has a 1/2" - 1 In. capacity. It weighs 10. 1 lbs. This set includes precise dies and die heads that are manufactured on CNC machines. It contains the drop heads and handle in a compact, reinforced plastic carrying case. The drop heads fit Reed's 601PD power drive. Heads up through 1-1/4" are interchangeable with Ridgid 11-R and R200, Super-Ego 600, Virax 1362, Rothenberger Super Cut hand ratchet threaders, and Supertronic portable power threaders.