Alumicore Grip Technically manufactured with a forged and CNC lathe-turned 6061-T6 aluminum tubing Grip comprised of Thermoplastic Velcanizate (TPZ) rubber sleeve and installed over the tube's knurled surface for traction and comfort Internal gear interface inside the AlumiCore Gripfor TBW is forged into the Grips aluminum sleeve, so it will never break or disengage from the TBW module's gear interface