Heavy Duty Hydraulic cylinder counter rotation that uses compression hoses 8M0053474 - 8M005053491. This cylinder is tested to Mercury's rigid standards that include higher loads and cycle testing to 300,000 cycles. It includes machined, high strength fasteners, electro polished SS arm, and heavy duty triple seal cartridges for enhanced duribility and longevity 135-300 HP OPTI Max Outboards and 4 Cylinder Verado (Hydraulic only). Fits:. Use on dual and triple installations (Counter rotation)