Trampoline Part Store&reg; 8 1/2" Ultra-grade* Trampoline Springs, Quantity of 10 Trampoline Part Store You say jump, we say how high? Replace your Springs with a set of our Made in the USA Springs Top Quality 8.5" inch Trampoline Springs made for the ULTIMATE, EXTREME BOUNCE!! Quantity of 12-per pack The Outside Diameter of our Springs are 1.1 inches, we use 8-gauge high tenacity steel Music wire, The Wire Diameter of our Springs is 0.125 of an inch thick (1/8 inch). The Measurement is Over The HOOK Trampoline Part Store fits any trampoline requiring the specific spring length shown, Plus or MINUS up to 1/4 inch 8 1/2" inch Trampoline Extension Spring, Farming, Ranching, Machinery, Maintenance, Home Repairs