Pro-Tect now offers it’s extremely durable Billet Aluminum Roll Chart, which clamps directly onto your handlebars. Other features include an easy access top pivoting cover, large user-friendly knobs, and a rolling action like no other. No need to worry about route sheets becoming bunched up either…there’s plenty of room on either side to accommodate even the widest of paper. Fits all models. Inside dimensions are 3"long x 2 1/4" wide x 1" deep.