Made of BUNA-N 70 durometer rubber compound. Creates a tight seal for fluid or gas connections. Handy kit for shop toolroom or toolbox. On hand when needed saves time and money. Plastic compartment box is easy to store. The Precision Brand 300-piece O-ring Assortment contains: 20 each of 3/32 x 7/32 x 1/16 in #005, 1/8 x 1/4 x 1/16 in #006, 5/32 x 9/32 x 1/16 in #007 and 3/16 x 5/16 x 1/16 in #008, 15 each of 7/32 x 11/32 x 1/16 in #009, 1/4 x 3/8 x 1/16 in #010, 5/16 x 7/16 x 1/16 in #011, 3/8 x 1/2 x 1/16 in #012, 3/8 x 9/16 x 3/32 in #110, 7/16 x 5/8 x 3/32 in #111, 1/2 x 11/16 x 3/32 in #112, 9/16 x 3/4 x 3/32 in #113 and 1 x 1-1/4 x 1/8 in #214, 10 each of 5/8 x 13/16 x 3/32 in #114, 11/16 x 7/8 x 3/32 in #115, 3/4 x 1 x 1/8 in #210, 13/16 x 1-1/16 x 1/8 in #211, 7/8 x 1-1/8 x 1/8 in #212 and 15/16 x 1-3/16 x 1/8 in #213, 5 each of 1-1/16 x 1-5/16 x 1/8 in #215, 1-1/8 x 1-3/8 x 1/8 in #216, 1-1/4 x 1-1/2 x 1/8 in #218, 1-3/8 x 1-5/8 x 1/8 in #220 and 1-1/2 x 1-3/4 x 1/8 in #222.