Thumler's MP-1 and Model T-100 Standard, Replacement Drive Belt 5 Pack These Belts Are Superior in Quality to Original Factory Rubber V Belts. "O" Ring Style Made From Buna Nitrile Has Greater Flexibility and Abrasion Resistance Than Natural Rubber These Belts have a 15 Year Shelf Life! They Stay Pliable Down To -20 F Please Note: These belts will only fit the new style tumblers