Haltec OR-25-T Standard 1/4″ Diameter O-Ring for 25″ Earthmover Tubele - Tire Supply Network
236 Buna O-Ring, 70A Durometer, Black, 3-1/4" ID, 3-1/2" OD, 1/8" Width (Pack of 25): O Ring Seals: Amazon.com: Industrial & Scientific
Amazon.com: KEX Single 25" inch Wheel ORing 15.5x25, 17.5X25, 20.5X25 Earth Mover Grader Tire O-Ring : Automotive
Centering Ring KF 25 With Viton® O-Ring, KF 25 (NW 25), Stainless Steel, The centering ring contains a rubber elastomeric o-ring. Those are also recognized as NW10, NW16, NW25, NW40, or KF-10