Ridgid 97050 Model 532 Bolt Die Head Quick Open 1 1/8" - 2" RH/LH Thread uses 500B dies. The Die Heads Quick-Opening Manually flip throughout lever to retract dies when Thread length is cut. Individual Machine Die Heads do not include dies. Bolt Capacity 1 1/8". This Die Head is for use With Ridgid's 535-535A-1822 Machines and 300 and 300-A w/carriage. The Model 532 Die Head replaces 500B Die Head.