The function of an hydraulic Wear Ring Wear Rings come pre-formed, or in strip form. Fabric-reinforced Polyester Resin - This strip material is for heavy-duty. Welcome to Tribotech Composites, Inc materials are made from proprietary blends of polyester composite resins, spherical bearings, wear pads, guide strips. SEALS Inch Wear Rings, Power Bands and Bearings F Flexible Guide Bearings-Polyester Resin. Size reference is marked every 6 in. on the strip.