The BH-75 – 7,500 lb. Advanced Flat Plate Boat Lift Hoist features 96-tooth bronze gear has all but eliminated friction build-up, because the gear that works the hardest, the worm, is made of hardened steel and enclosed in an aluminum housing. Solid aluminum extended block housing that strengths and supports the back plate. This reduces heat build-up caused by friction and keeps the worm gear greased and aligned. No steel on steel moving parts. The completely enclosed worm, bronze composite backplate bearing, and aluminum pulleys combine to lift up to 7,500 lbs at 24″ per minute without any compounding. This allows for a more economical and lighter weight 1/4” back plate. The BH-85 uses a 10” drive pulley system.