ITEM NAME:5 Pcs Black Nitrile Rubber O Ring Acrylonitrile Butadiene Seal Grommet 50mm U9K4 5 Pcs Black Nitrile Rubber O Ring Acrylonitrile Butadiene Seal Grommet 50mm U9K4 The NBR nitrile rubber O ring is oil resistant, abrasion resistant and waterproof. Are widely used on Automotive components, machinery components, medical and sanitary equipment, household electrical appliances and electronic instruments, etc. Product Name: O Ring Material: NBR (acrylonitrile butadiene rubber) Color: Black Inner diameter: 42mm / 1.65 inch Outer diameter: 50mm / 1.97 inch Thickness: 4mm / 0.157 inch Weight: 14g Package Contents: 5 pcs x O Rings Only the above package content, other products are not included. Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/-1-3cm..Material: NBR (acrylonitrile butadiene rubber). The NBR nitrile rubber O ring is oil resistant, abrasion resistant and waterproof. Color: Black.