Two-Bottle rear mount hydration system clamps to standard round diameter bicycle seat posts (31.6mm or 27.2mm). Affix two CO2 cartridges with included brackets.

New reinforced design.
Includes 2 lightweight Profile Design Kages.
Includes CO2 mounting brackets. Allows for mounting of two 12g or 16g threaded CO2 cartridges.
Fits 31.6mm to 27.2mm round diameter seatposts (shim included).