This is essentially a way to take 42oz (1.25L) of water with you on a hydration system that's off your back and on your bike.
It comes with a small carry compartment (It was too small to fit my smartphone, unfortunately) separated by partition so you can carry small essentials like house keys or a multi-tool, plus keep it separate from valuables you know could get scratched if the mesh barrier wasn't there. It was very easy to install, and after some initial tweaking of where each retractable cable should go, I found it easy to have this tube to drink from and retract back to the bike, out of the way. I didn't have this thing getting caught on my components or in the way of my pedaling. If you cut the hydration tube, make sure when you reattach the tube to the bite-valve drink valve that there's a good seal, or else it won't deliver the water. I also suggest being careful how short you cut the tube, as I did it more by the installation diagram visually, but discovered when I was riding and drinking from the tube that it wasn't long enough for me to use when I was pedaling off my seat and climbing a hill. You can always cut off more tube, but you can't grow it back for the added length.
I'm a little wary the cables used to retract the tube back to my bike are thin and will break, but according to the product description online they're built from a 3-ply pylon parachute cord tested a zillion times, and so far so good. I also like how easy it is to take off and put back onto your bike, so if you have a few bikes for various different biking activities you can easily transfer this between bikes or keep if off your bike when you're bike's on your car and on a bike rack like the Saris Superclamp 2-Bike.
The outer material is somewhat reflective as well, and since this attaches under your bike seat, it's nice to add a new visual spot to oncoming vehicles that's meant to keep you safe.