ZEC - Litex Grinding Disc/Wheel 4 1/2" S/C 16 GRIT HD Disk 4 1/2" ZEC Litex S/C 16 Grit Heavy Duty Disc The Litex disc has a plastic back and does not require a backup pad. The Litex lasts up to 7-10 times longer than conventional aluminum oxide resin fiber discs. The Litex disc design minimizes the loading of material being ground on the disc. The Litex cuts faster than a conventional grinding disc.