The DYNABRADE's 51134 series Dynastraight flapper air-powered abrasive finishing tools feature a diameter of 8", 0.5 HP, 1/4" collet, adjustable speed up to 18,000 RPM, rear exhaust, 1/4"-20 female thread, level throttle, front exhaust, and are used for polishing insides of pipes and tubing, light deburring, dust, oxide and scale removal, clean welds, paint removal and surface conditioning via abrasive flap wheels.