Supertech Part Number SPRK-MM18S includes 16 Valve Springs, 16 Titanium Retainers and 16 Valve Spring Seats. Supertech Valves are sold separately on our site for a complete upgrade. Here are the Specs of the SPRK-MM18S valve spring kit:

Valve springs are made with premium Superclean Chrome Silicon Vanadium Steel alloy for higher performance & durability at high rpms and better memory. Computer designed to ensure that wire stress levels do not overpass the limits of stress defined in the diagrams of fatigue for long durability under extreme conditions. Computer software also allows us to make sure that the harmonics arewell under control. The Retainers are manufactured with high quality military certified Titanium alloy, CNC machined for a tight fit that will ensure a long durability.