Reduces 3/8″-16 Thread down to 1/4″-20 Screwdriver Slot for Easy Removal Durable Stainless Steel Bushing This 1/4″-20 to 3/8″-16 Reduction Screw from 8Sinn enables you to mount a 1/4″-20 threaded accessory in a 3/8″-16 thread. A flat head screwdriver slot enables you to easily mount and remove this stainless steel bushing.