ITEM NAME:200PVH 20 Sizes Springs Practical Metal Tension/Compresion Springs Assortmen3C.Compresion Spring Flexible springs are both sturdy and springy for the right amount of tension. Tension spring Material: Spring steel. Color: Silver. 5.55 38.1mm/10PCS. 9.12 34.9mm/8PCS. 9.52 19.05mm/12PCS.