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
uxcell Nitrile Rubber O-Rings 14mm OD 10mm ID 2mm Width, Metric Sealing Gasket, Pack of 20: Amazon.com: Industrial & Scientific
uxcell Nitrile Rubber O-Rings, 20mm OD 16mm ID 2mm Width, Metric Buna-N Sealing Gasket, Pack of 20: Amazon.com: Industrial & Scientific
MT MORN0520020-52mm X 56mm X 2mm O-Ring (10 Pack): Amazon.com: Industrial & Scientific