Amazon.com: uxcell Nitrile Rubber O-Rings, 6mm OD 2mm ID 2mm Width, Metric Buna-N Sealing Gasket, Pack of 1 : Industrial & Scientific
uxcell Nitrile Rubber O-Rings, 12mm OD 8mm ID 2mm Width, Metric Buna-N Sealing Gasket Pack of 20: Amazon.com: Industrial & Scientific
Amazon.co.jp: DINGGUANGHE CS1.2mm Silicone O-Ring OD 16/19/18/20/22x1.2mm Japanese VMQ Gasket Seal Thickness 100PCS White Red Rubber 1.2mm Logical Gasket, Ring (Size : OD18x1.2mm Red) : Industrial & Scientific