Listing is for One Rubber O Ring Made of Nitrile Rubber N3. 

The Outside Diameter = 120 Millimeters or ~4.724 inches or ~ 4 & 23/32nd inches

The Inside Diameter = 115 Millimeters or ~ 4.527 inches or ~ 4 & 17/32nd inches

The Thickness = 2.5 Millimeters or ~ .0984 inches or ~ 3/32nd inches

These Resist oils, hydraulic fluid and water.

Flexible nitrile rubber O ring seal.

These O ring are used on automotive components, machinery components, medical and bathroom facilities, household electrical appliances and electronic instruments, etc.