Partstock(TM)Bicycle Water Bottle Cage Lightweight Easy to Install. LIGHTWEIGHT Strong toughness plastic: High quality material and manufacturing for extra strength and durability yet lightweight. 2 X M5 SCREWS INCLUDED: No need to go looking for the right screws. The included screws are standard size for mounting bicycle water bottle cages EASY INSTALLATION: Use a 4mm hex key (Included) to fasten cages in threaded screw holes on frame. FITS MOST STANDARD SIZED WATER BOTTLES LIFETIME WARRANTY: This product is covered by Partstock Lifetime Warranty