Dropheads fit Reed 601PD and are interchangeable with RIDGID? brand 11-R and R200 (through 1 1/4in), Super Ego? 600, Virax? 1362, RothenbergerTM Super Cut hand ratchet threaders and Supertronic portable power threaders. Complete heads with alloy dies are priced lower than alloy dies sold alone for the most common manual threaders. Separate replacement dies not available. Heads available in NPT. Use R11SC ratchet ring and handle (#05230) with 1/4in to 1 1/4in dropheads. Use R20 adapter to use R11 heads in R20SC (1 1/2in to 2in) ratchet ring and handle.