Triathlon Water Bottle / Tire Holder (seat post mount 27.2, & 31.5)

Designed for Triathlon specific purpose but can be used as a cage mount for any bike with 27.2 seat post. Snaps on to seat post then zip ties in place (found that a wrap of electrical tape under it helps it to stay put and not rotate as easy).
Bottle cages mount with #10 x 1/2" screws and nuts, there are recesses to hold the nut from turning so only a screw driver is needed.
The area between the water bottles is meant for a road tube (I like to add tube infiltrator and quick sticks into a zi