For use on any silver, black, red, blue and dark gray dynaflex models, 5 Star Silver Super Close Foil (item number 07031-400), Wahl recommends changing the foil every 6 months for a closer, more comfortable shave, Fits all custom shave, dynaflex models including 4400, 4500, 4000, 3500, 7035, 7053, 7054, 7355, 7359, 7352, 7353, 7354, 7356, 7357, 7358, 7367, 7386, 7387, 7388 and id shavers and system 4000, Replacement foil for wahl custom shave systems