Vktech&reg; Gub 328 Mountain Bikes CNC Aluminum Headlight Flashlight Mount Lamp Holder Super light CNC Aluminium alloy body and extender bar Material: mount for aluminum alloy material, circle wising for aluminum alloy material Suitable for installation handlebar diameter 31.8 mm Fixed the column diameter 2.2cm, length 84cm Fits on to your bike handle bars to add extra storage space for your bike lights, GPS or phone etc