WTB Comfort Zone Clamp-On Bicycle Handle Bar Grips The large, soft platform dissipates forces onto a greater surface area, preventing hand soreness and pain. Soft DNA rubber and smooth edges make the Comfort Zone grips a best seller among all rider types. Dual clamp-on Black Medium (30mm) diameter. Ergonomic shape WTB DNA rubber Designed use: City/Trekking/Comfort