N60012 replacement O-rings are specifically sized for use on the thread types listed below. These O-rings are made of 90 durometer neoprene which resists gasoline, oil, grease and petroleum based hydraulic fluids. N60013 O-ring kits are available for the individual who needs to keep a variety of O-rings easily accessible. These kits are complete with carrying box which has labeled individual slots for each type of O-ring.