S.I. Feeders Products In Stock New 2018 S.I. Feeders 24FT ARROW FRONT THE ORIGINAL HAY FEEDER TRAILER!!!!!THE BEST MONEY CAN BUY!!!CALL FOR PRICES. 800-669-6450 New S.I. Feeders 24' SI Feeder Wagons we have units in stock ready to feed Hay Wagons S.I. Feeders Arrow Front Feeders20' / 24' / 32' Other sizes and models also available, including Pan Bunks, One Sided Bunks, Trailer Bunks.