Features: Made of high quality rubber material, these O-rings are durable and has longer service life. 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. 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. Specifications: Material: Rubber Type*Qty*Inner Diameter*Section Thickness: R-01*20pcs*3mm*1.5mm R-02*20pcs*4.4mm*2mm R-03*18pcs*5mm*2mm R-04*23pcs*7mm*1.5mm R-05*23pcs*10mm*1.5mm R-06*23pcs*13mm*1.5mm R-07*14pcs*10mm*2.5mm R-08*13pcs*11mm*2.5mm R-09*14pcs*13mm*2.5mm R-10*13pcs*14mm*2.5mm R-11*14pcs*16mm*2.5mm R-12*14pcs*18mm*2.5mm R-13*13pcs*19mm*2.5mm R-14*14pcs*21mm*2.5mm R-15*13pcs*22mm*2.5mm R-16*10pcs*18mm*3.5mm R-17*10pcs*20mm*3.5mm R-18*10pcs*22mm*3.5mm R-19*10pcs*23.5mm*3.5mm R-20*10pcs*25mm*3.5mm R-21*10pcs*26.5mm*3.5mm R-22*10pcs*28mm*3.5mm R-23*10pcs*30mm*3.5mm R-24*10pcs*31mm*3.5mm R-25*10pcs*33mm*3.5mm R-26*10pcs*34.5mm*3.5mm R-27*10pcs*36mm*3.5mm R-28*10pcs*38mm*3.5mm R-29*10pcs*41mm*3.5mm R-30*10pcs*44mm*3.5mm R-31*10pcs*47mm*3.5mm R-32*10pcs*50mm*3.5mm Package Includes: 1 box * O-rings .