Johnson Level 40-6210 GreenBrite Magnetic Sheave Alignment Kit, Gold Decrease vibration on any pulley sheave system-minimize belt and motor bearing wear Compact size - easy to use on small diameter sheaves allows for faster set ups Use as a laser level- check the height and flatness of motor and gear box mounting plates Laser Class ll Power output Less/Equal to 1mW Used by millwrights and plant maintenance managers