... ring ensure moisture proof environment.Cone-shaped nut have lines in order to prevent from rotation ... or stainless steel.Assemble:bolt,nut,washer,water-proof plastic ring,cone-shaped nut,sleeve. Coating: Cr6 zinc ... /Cr3 zinc,3-5micron,WZP of YZP. Bolt:grade 4 ... ring ensure moisture proof environment.Cone-shaped nut have lines in order to prevent from rotation ...