At only 1.8 lbs. this Howe hydraulic throw out bearing is the lightest available. It is not made from a porous casting, but from tough billet aluminum. Compatible with most reduced diameter racing clutches including Quarter Master and Tilton. The unit installs by simply removing two of the bearing retainer bolts and replacing them with the provided studs. The optional remote bleeder kit (8289) allows for easy bleeding of the system outside of the bell housing. This throw out bearing will not work with a stock clutch or Ram coupler. Fully compressed, the unit is 2-3/8" thick and will need at least .060 working clearance. Fully extended it is 2-3/4" thick extended providing 3/8" throw.