Hand made original "Kalamazoo Line". The B7 model is best suited for thin archtop hollowbodies & solid body electrics such as Gibson ES-335, Les Paul, Heritage H-535, Epiphone Sheraton, Alley Cat, Dot's, etc... that have a stud mounted Tune-O-Matic style bridge. These units have the roller retaining bar to give you the angle over the bridge that is needed. Requires two holes to be drilled into the top of the guitar & four on the bottom where the hinge attaches to the body. All mounting hardware is include. Bridge not included. Overall length 8.75 inches / 222.3mm, overall width 3 and 5/8 inches.