Suitable for NEW BIRDY Adjustable Forging Stem. ((Both of 10 degree and 21 degree)) Material : 6061T651 Screw : SUS (Stainless) Production method : Extrusion die & CNC Machined Weight : 48 g ———————————————————— Stable in riding and could be a perfect position in folding. The rubbers used in the interior with dampening effect. To keep the bottle stable in riding. Before bike folding, to slide the bottle klick forward and rotate it 90 degrees to the right. When the front stem fully folded, it will not injure the frame.