the original GP1 ergonomic grips set the global standard in ergonomics, comfort, materials and quality. Grips effectively counteract hand numbness, finger pain and forearm fatigue.the aluminium sleeve fixes the grip in place and prevents it from moving while riding, while allowing perfect adjustment of the grip angle. Grips are compatible with carbon handlebars. BioKork grips are made from 40% cork and take advantage of its unique properties. The grips are antibacterial, hypoallergenic and the cork has natural cushioning properties. The cork comes from sustainable forests in Portugal and is certified for its organic production. The ecological processing accompanies the entire production of the grip.the inner core is made of reinforced plastic using natural fibres, which make up 20% of its weight. The Gripshift version has both grips shortened specifically for Gripshift / Dual Twist shifters. Material: cork, Certified rubber compound Sleeve: Aluminum Use: MTB, travel, commuting