The STANLEY GR60 Cup Stone Grinder was designed to meet the rugged grinding needs of the railroad industry. It contains a hydraulic motor specifically designed to match power and rpm for grinding applications. A built-in flow control is used to avoid excessive spindle speed. For added safety the GR6O contains an interlocking trigger which prevents accidental engagement of the tool. It also features a rugged cast aluminum guard combined with a single latch guard height adjustment. No tools are required to adjust the height. And it meets ANSI and OSHA standards.