U-shaped rack with double-toothed edges made of 2.5 mm thick steel.
Rounded tooth reduces wear and reduces friction between rack and pinion. The pinion cage, made of galvanized sheet, has 3 locking points that guarantee a secure fixation; its 2 rollers provide smoother sliding of the stick. Sprocket, in self-lubricating synthetic material, is attached to the drive tube with 2 sets of 8x1 bolts