Slackline Kit, Oumers Complete Slackline Set with 50ft x 2in Balance Training Line Tree Protectors Ratchet Gloves and Carry Bags Ergonomic shaping optimizes comfort and absorbs shock, make you feel very comfortable on long rides around town. With antiskid outer convex TPR rubber grip, you can still grip even your palm sweats in hot days The body use TPR rubber material,completely nonslip,dexterity is similar to silicone Will fit any standard straight bicycle or stunt scooter handle bar Inner diameter:About 2.5cm.