Able to accommodate the heaviest routers, this thermoset 3/8-inch base plate measures 9 by 12 inches with a 1/4-by-1/2-inch lip, and allows mounting in 3/4-inch tops. Two rings snap out to accommodate larger router bits up to 3-3/4 inches with opening sizes of 1-1/4 (designed to fit template guides), 2-5/8, and 3-7/8 inches. The shoulder pin can be used in any of five locations for ease in starting freehand work. Also included are four corner Snuggers to remove excess play if the opening doesn't exactly match the base plate and to securely mount the plate to the top. The base plate is molded with a slight crown to ensure the center is the highest point.