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.