9pcs 48x2.5 48*2.5 50x2.5 50*2.5 52x2.5 52*2.5 (OD*Thickness) Green Fluoro FKM Fluorine Rubber O Ring O-Ring Oil Seal Gasket - AliExpress
O-Ring 50x2,5 | BR 05 0032
Ideal Vacuum | Leybold Piston Rings for WA/WAU/WS/WSU 2000/2001 Blower Booster, 45x2.5 mm, material DIN34110, 1 each, 23153216 231 53 216 Sold as one each