... time. 4.1500-2000 Hours guarantee 5.ISO9001:2008 1.Product Specification Material50MnQualityHeat-treated,HRC49-56,Depth 5-8mmColorYellow or ... of excavator and bulldozer undercarriage parts and auto parts,including track roller,top roller,track chains,idler groups,roller,bushings and pins,bolts& ... 7/083/181,FR60-7Mutual profit is our pursuit Track roller bottom roller lower roller for excavator T320