Outer Diameter of the Spring Ring--Approx. 34.4mm / 1.4in; Inner Diameter of Spring Coil: Approx. 28mm / 1.1in; Wire Diameter: Approx. 3.18mm / 0.1in Carbon Steel Material--It is made of carbon steel material, which is and practical to use Cushion Working Machine--There is a 150, 190 and 250 general air hammer retaining spring, which can cushion the working machine Easy To Replace--It has small body and stable performance, which is easy and convenient to replace Application--Fit for automotive industry, sheet metal industry, tire repair industry, construction industry, machinery factory production line and so on, Manufacturer: SEAFRONT