Made to mill matching frame joints for wainscoting in stock from 1/2" to 5/8" thick. The bit height is set one time for both male and female joints, with no further adjustments to bit height or fence position. Just rout stiles face down and rails face up for a perfect fit. The versatile design also lets you rout a rabbet on the back of frames to accept the tongue of a 3/4" thick raised panel. Carbide tipped. Italy