This Gear is a steel upgrade replacement for the plastic Pulley only # 210921 is 1 3/4"x5/8" for a MOORE-O-MATIC Garage door opener model XX150,XX133,XX333,XX350 chain drive with T-rail . This is new and is in excellent condition, this upgrade won't crack or wear out like the original. Guaranteed to fit perfectly. This is the gear only the pics that show the complete adjuster and mount are for reference only to show how it is used. I do have some other parts available just message me as to what you need. stk#(271)A13,B-1
