Upgraded tensioner kit for 4405 bracket kits. This tensioner has a shouldered pulley to aid in belt alignment in high RPM/ high HP applications, and also off-road vehicles.
Spring tensioner kit for 4405-20, 4405-10, 4419 bracket kits. This tensioner has a smooth pulley. You can swap the pulley with the 4461 that has shoulders to help with belt tracking