Crosman Bolt O-Ring - .177 or .22 - Fits 1377 1322 2240 2250 2289 2260 2300KT 2400KT This is the standard OEM genuine Crosman bolt o-ring found on COUNTLESS discontinued and in-production models. This is the o-ring that slips onto the brass or steel bolt that then mates with the breech. Will fit AT LEAST the following models: 1377 1322 2240 2250 2260 2289 2300KT 2400KT, etc.