Everbilt 2-3/8 in. x 2-1/8 in. x 1/8 in. Buna Rubber O-Ring 837468 - The Home Depot
208 O-ring 5/8" ID x 7/8" OD x 1/8" thick. Buna-70. Quan 5. | eBay
FITTING, .250 SS BARB X .375 O-RING ASSEMBLY - 625-0004 | Beverage Equipment and Parts Distributor - Apex Beverage Equipment - Bargun Parts and Accessories - Bargun Parts and Accessories Beverage Equipment and Parts Distributor - Apex Beverage Equipment