.904? diameter; 110g weight; 1.91? seat height; Patented orifice metering valve precisely meters oil to the rocker arms; Continuous contact between metering valve and hardened pushrod seat is maintained, eliminating excessive oiling at high engine speeds; Contain a longer piston than conventional Hydraulic lifters, which provides more load bearing surface and increases lifter longevity; Lightweight check valve disc allows for quicker response and maintains added control at all engine speeds and loads