Don't let your water slip or rattle any longer as you bike down the path. The Topeak Modula(TM) II Bike Bottle Cage adjusts to both traditional cycling bottles as well as store-bought bottled water containers. Just push the button and slide the bottle to fit. The cage is constructed of engineering grade polymer and aluminum for durability. FEATURES: Diameter adjustment system Aluminum and engineering grade polymer construction Fits traditional cycling water bottles to store bought bottled water containers Outer diameter: fits 2.5" - 2.9" Dimensions: 6.2" x 3.4" x 3" Weight: 2.53 oz.