Gomadic Bike Handlebar Holder Mount System suitable for the TomTom XXL 550 - Unique Holder, Lifetime Warranty Cradle attaches to handle bars of any bike with tube diameters ranging from 1/2 - 1 1/8 inch (13-28mm). Unique rubber ribbed clamping system connects without the need of tools. Bike handlebar mounted base for the TomTom XXL 550 device. Cradle is designed to accommodate the specific dimensions (132.1 x 89.6 x 23.8 mm). Perfect for bikes (street or mountain) and also works great on motorcycles, ATV, 4-wheelers, golf carts, baby strollers, snowmobiles and more! Specifications: Holder Base: (2.5 X 4.0 inches in closed position. Highly expandable), Handlebar Mount (13-28mm tube diameter), Weight (Base 4oz., Mount 2oz.) Simple operation. Quickly, safely and securely installs in minutes.