The stem mount is designed for Polar M450 V650 GPS computer,1-1/8 34; diameter 5mm height stem mount, it cantightly attached to your bike. Made of CNC-machined aluminum,durable and strong, ideal for mountain bikers. Features: Designed for Polar M450 V650 GPS computer. 1-1/8 34; diameter 5mm height stem mount, tightly attached to your bike. You can adjust the angle of the mount, easy to use. Made of CNC-machined aluminum, durable and strong enough. Specifications: Material: CNC Aluminum 43; Plastic Compatibility: for Polar M450 and V650 Item Size: 8.5 * 3.6 * 1.4cm / 3.35 * 1.41 * 0.55in Item Weight: 26g / 0.92oz Package Size: 10 * 8 * 1.5cm / 3.94 * 3.15 * 0.59in Package Weight: 65g / 2.3oz Package List: 1 * Stem Mount 2 * Hexagon Wrench 1 * Hexagon Screw Note: Bike computers are NOT included.