Vision Metron Rear Hydration System Aero Mounting Integrated Bottle Cage Triathlon Use – BLKVision Metron Rear Hydration System. The Modular Saddle Drink System is a lightweight precision engineered hydration solution that fits both traditional and snub nose saddles. It offers customizable mounting options and includes two high grip carbon cages for secure bottle retention. Universal fit with 3 position saddle rail and 5 position bottle cage tilt adjustments Multiple lashing points for water bottles CO2 pumps accessory bags and tie straps