Rubber disc returns are used to support the belt on the return side when the conveyed material is sticky or abrasive. The spaced rubber discs flex and offer relief to avoid material build up caused by excessive carryback. Rolls have flat, massed rubber ends to offer support if the belt mistracks from center. Martin Rubber Disc Return Idler, C CEMA, 4 in Roll Diameter, 30 in Belt Width, Sealed Ball Bearing, 33.13 in Roller Length, 41 in Overall Width, 39 in Distance Between Mounting Holes