They are wearable, corrosion resistant and high temperature resistant. There are 32 different sizes of O-rings in this set that can meet your different need. Made of high quality rubber material, these O-rings are durable and has longer service life. Total 419 pieces so you do not have to worry about running out of O-rings for quite a while. They can be widely used for sealing for valves, cars, pumps, electrical equipment, bearings, etc.