1、1. Lightweight and durable: It is made of 6061 aluminum alloy, which gives the cage extra strength and durability. Each holder weights only 50g, and you will hardly notice its existence! 2、2. Bottle cage: Generally suitable for standard size water bottles-suitable for most bicycle water bottles. The one-piece flexible shape design is suitable for smaller bottles. 3、3. Quick and easy installation: Install these cages in less than 60 seconds. Use a 4 mm Allen key (not included in the scope of supply) to fasten the stainless steel bolts to the bicycle frame. Important note: It requires threaded holes to install the bottle holder. The cage design is only installed on the bicycle frame down tube and the seat post tube. 4、4. Practical: It can be directly locked on the seat bow and can be extended to add two bottle cages for long-distance riding without worrying about drinking water! 5、5. Multi-function: The bottle cage can be rotated 360°, can carry gas cylinders, can be equipped with two bottle cages and other functions, a single bottle can be installed in other positions such as the front/seat tube. Material: 6061 aluminum alloy Weight: single bottle cage: about 50g/ double bottle cage: about 80g Suitable for 21-31.8 pipe diameter, suitable for most water bottles 1 * Bottle Cage