CNC machined aluminium knobs by Biltwell inc. After precision machining and surface detail, a vulcanized thermoplastic rubber (TPV) sheath is installed on the knurled surface of the tube for traction and comfort. This highly UV-resistant material is soft and comfortable, but extremely durable. The AlumiCore knob on the clutch side has an internal wedge system on the end cap that expands inside the handlebar to eliminate any possible slippage or play of the knob. They are sold in pairs. The TPV rubber sleeves on the knobs are black, but you can replace them with spare parts in other colors that you can find on our site (art. 204837, 204838, 204839, 204840, 204841).