Arbor Pulley 5-1/2 for 1725 RPM Motor. his is a brand new pulley CNC machined from 6061 aluminum billet. Superior to the original Arbor Pulley for older Delta or Rockwell Unisaw with Repulsion Induction Motors sometimes referred to as Torpedo or Bullet Motor #'s 85-01087-010 87-210. 3/4 Inch Bore 3 V's for standard 1/2 inch or A V Belts. These pulleys are made to order and may take several weeks to ship. Order 49-291 if you also need the belt set.