The Speedfill Hydration Z4 Plus Cage System is designed to be used with the A2 bottle for a complete system to keep you hydrated throughout your ride. Unlike upright bottles that secure with over sized rubber bands, the Z4 attaches securely to the extensions with nylon cable ties. This top of the bar positioning means that bar width is no longer dictated by the width of your bottle. Additionally, the Z4 integrates a removable arm that houses the Garmin quarter turn bike computer mount sold separately so that your metrics will always be in plain view. The additional pieces included in the Plus system are an additional non slip strap to keep your A2 bottle system from rotating as well as a tube clip that holds the drinking tube out of the way while you are not using it.