What is the benefit of installing these shell-type wheel bolts? Based on common lug bolts, BONOSS has upgraded the exterior of traditional lug bolts, matching the bolt with a shell for protecting the bolts from debris and water corrosion and maximally beautifying your wheels. The main part of the bolt is made of high-strength SCM440 alloy steel, after the forging process by BONOSS factory, they have fully passed ISO Grade 12.9 performance test, tensile strength≥1,282Mpa, limited life range test≥2,000,000 stress cycles without damage, ultimate tensile load≥152,000N, hardness (HV)≥395, NSS≥192H…. The shells of the bolts are able to change, in BONOSS stock, we have eight colors to meet your needs. Changing to new lug bolts is not expensive, but it is the fastest part of enhancing the visual effect.