This listing is for the purchase of one RED O-ring. Round, RED o-rings are used for all 24 bolt rims and 12-bolt HUMVEE rims (and M1101 and M1102 trailers) with the extra alignment hole in the 2 halves of the wheel). Round, BLACK o-rings are used for 12 bolt rims (never 24 bolt) with NO alignment hole in the 2-Halves of the wheel. Red O-Ring For 16.5” 2-Part Split Rim Wheel - Military - HUMVEE M1102. These gaskets will work on military Tires such as the 37” military Humvee tire and also on military trailers such as the M1101 and M1102. All of those tires are on 16.5” rims with 8 mounting lugs and either 12 or 24 bolts connecting the 2 halves of the wheel together. Condition is “New”. Part # 12460338