... developed for use with banjo bolts and rings 1.Washer Type: Copper washer,aluminium washer,O-ring,Twin rings,heat shield Twinrings were ... and rings.2.Materials: Copper, Aluminium, AIMg3, AIMgSi1, Steel, Armco, Spring Steel (Ck67,Ck75, 51CrV4, etc.), 15 Mo3 (16Mo3), 13CrMo44, Stainless ...