ESTABLISHED USA brand Pearl Abrasive Red-Line MAX-A.O. Aluminum oxide depressed center grinding wheels. SPECIFICATIONS: for grinding stainless steel, iron and steel. Aluminum oxide. Grit A/WA24R. T-27. 30 degree angle. Max RPM: 13,300. With hub. Refer to listed spec chart for other specs. FEATURES: one-third more efficient than standard Aluminum oxide. LESS VIBRATION: wheel offers near perfect balance, with significantly less vibration or "Wheel chatter." COOLER GRINDING: wheel runs significantly cooler than other wheels. MULTIPLE CUTTING EDGES are with rates that are significantly higher. INCREASED GRINDING EFFICIENCY: designed with cutting efficiency in mind, providing greater productivity for the operator. PACKAGE of Five (5) grinding wheels. US based welding supplier. Strong technical support with experienced customer service to address buyer's any question.