PFERD Comb click Aluminum oxide a-cool fiber discs are designed for general-purpose grinding, from coarse to ultra-fine, on poor heat-conducting materials. Active additives in the coating ensure substantially increased stock removal while preventing loading and heat build-up in the work piece. Comb click system combines an innovative flexible backing pad with a quick, easy and rugged mounting system on the back of the disc. The backing pad allows comb click discs to be used with standard angle grinders. The geometry of the cooling slots ensures a high throughput of air, thus significantly reducing thermal loads on the abrasive material and work piece. The rugged mounting fixture, secure disc attachment to the backing pad plus optimized cooling help to provide: up to 30 percent lower work piece temperature, up to 25 percent increased stock removal, up to 30 percent longer service life and improved utilization of abrasive product and up to 30 percent less tool wear. Specification: Diameter: 5"; Max RPM: 12,200; Grit: 220.