For FRB-770 band sealers, this pack of 10 brown PTFE Teflon belts provides replacement sealing and conveyor belts. The belts are thin brown endless loops held together with a yellow tie. They carry the bag mouth past the heating and cooling blocks of the FRB-770 during continuous sealing, and the heat-resistant PTFE material suits that contact, making the set a practical maintenance spare for packing lines.