The Friendly Swede Alloy Bicycle Water Bottle Holder Cage (2 Pack) 6061-T6 HEAT-TREATED ALUMINIUM ALLOY: High quality material and manufacturing process for extra strength and durability combined with low weight, 2.1 oz (60 g) each 4 X M5x0.8 SCREWS INCLUDED: The included screws are standard size for water bottle mounts EASY INSTALLATION: Use a 4mm hex key (NOT included) to fasten cages in screw holes on frame. PLEASE NOTE - bike frame requires threaded holes for installation of cages FITS MOST STANDARD SIZED WATER BOTTLES LIFETIME WARRANTY: This product is covered by The Friendly Swede's Lifetime Warranty 2 X Bicycle bottle cages 4 X M5x0.8 Screws