The XLAB Delta 430 XT Rear Hydration System is an efficient and aerodynamic way to carry your spare bottle, tucked behind your saddle. This version is only compatible with ISM PN 3.0, PN 3.1, PN 4.0 saddles. You can even adjust the cage angle and height for a custom position. The XT version of the Delta comes equipped with a Gorilla XT cage which features 14 pounds of grip. This lightweight carbon cage offers stable mounting and an anti-vibration design as the stiffest cage on the market. The XLAB Delta 430 XT Rear Hydration System is the perfect way to carry an extra bottle.