Made of fine NBR rubber material has high resilience, proper mechanical strength and pliability. Stable property and easy to process and keep the precise size, this box of 0-rings can meet your various needs. Specifications: Package Size: 200 * 150 * 50mm / 7.87 * 5.91 * 1.97in Package Weight: 632g / 1.39lb Including: R-01 * 20PCS 3 * 1.5mm R-02 * 20PCS 4.4 * 2mm R-03 * 18PCS 5 * 2mm R-04 * 23PCS 7 * 1.5mm R-05 * 23PCS 10 * 1.5mm R-06 * 23PCS 13 * 1.5mm R-07 * 14PCS 10 * 2.5mm R-08 * 13PCS 11 * 2.5mm R-09 * 14PCS 13 * 2.5mm R-10 * 13PCS 14 * 2.5mm R-11 * 14PCS 16 * 2.5mm R-12 * 14PCS 18 * 2.5mm R-13 * 13PCS 19 * 2.5mm R-14 * 14PCS 21 * 2.5mm R-15 * 13PCS 22 * 2.5mm R-16 * 10PCS 18 * 3.5mm R-17 * 10PCS 20 * 3.5mm R-18 * 10PCS 22 * 3.5mm R-19 * 10PCS 23.5 * 3.5mm R-20 * 10PCS 25 * 3.5mm R-21 * 10PCS 26.5 * 3.5mm R-22 * 10PCS 28 * 3.5mm R-23 * 10PCS 30 * 3.5mm R-24 * 10PCS 31 * 3.5mm R-25 * 10PCS 33 * 3.5mm R-26 * 10PCS 34.5 * 3.5mm R-27 * 10PCS 36 * 3.5mm R-28 * 10PCS 38 * 3.5mm R-29 * 10PCS 41 * 3.5mm R-30 * 10PCS 44 * 3.5mm R-31 * 10PCS 47 * 3.5mm R-32 * 10PCS 50 * 3.5mm