Robax Heatwrap Neck/Shoulder have patented heat cell technology to soothe your stiff, tired neck and shoulders after working in front of your computer all day, driving long distances, sitting stuck in traffic, or whatever you were doing to make your neck and shoulders ache. You can enjoy up to 16 hours of relief with 8 hours of heat, then take it off and enjoy another 8 hours of relaxed neck and shoulder muscles so you can rest. Each wrap is thin, discreet, and odorless so you won’t smell like a medicine cabinet.