Variable speed models allow stepless control of drilling speed between minimum and maximum enabling finer control of finish and tolerance. The belt transmission uses two spring tensioned cone pulleys, the diameters of which can be adjusted by moving a centre idle pulley with the speed adjustment control lever. Meets CE Machinery Directive 98/37/EEC, Low Voltage Safety Directive 79/23/EEC and EMC Directive 89/336/EEC. Safety devices fitted include a no-volt release switch, allowing insurance company approval for use in educational establishments. Supplied with chuck guard.