CanDo® Half Round Foam Roller, Extra Firm, 6 x 36 Inch, 1 Each Food Bumpers *Dual Independent Channels *Adjustable timer Imaging *Dual Independent Channels *Adjustable timer on standard and digital units *Adjustable Frequency and Pulse Duration parameters *Basic and Standard units feature three modes: Burst Normal and Modulation *Digital units feature 5 modes: Burst Normal Modulation Rate and Width Strength Duration and Bi Pulse * Digital unit has easy to read LCD Display and convenient digital controls * (5) adjustable height metal legs these rollers are durable as they feature premium molded foam that is firmer and more rugged than polyethylene Closed cell black composite material so the roller is easy to clean