Genuine Mahindra fan belt (part #31S9401130, alt #99940002030) for 2815, 3215, 3316, and 3616 tractors. Ensures proper cooling system operation and belt-driven accessory
billstractor.net
Whenever I need a belt, I normally just remove the old belt and take it to the local car parts store. They normally stock V-belts of just about any length (down to the closest inch).