Quality/Rockwell 12-1/4" x 3-3/8" 9,000lb-10,000lb General Duty(5 bolt flange) Left hand electric brake. Complete assembly. Self-adjusting design keeps shoes properly aligned for longer-lasting brake that requires less maintenance. Mounts with 5 studs that are pressed in to place. Uses a 6-46 lock nut (Sold separately) to mount to the brake flange.