Carbon storage system.
The Lezyne Carbon Cage uses FCT structural carbon to shave crucial grams and features upper and lower catches so your bidon won't eject mid-race. An integrated low-profile pump bracket is molded directly into the cage body to save weight and space when paired with a Road Drive-style hand pump. You can't make your water any lighter, but this is the next best thing.
The Lezyne Carbon Cage is compatible with standard-circumference water bottles and can be used on both small and large frames.