This is what your bottle belts look like when they arrive in the mail: an instruction packet and two belts. We're going to fit it on your bike in a figure "8" shape.
Standing over the top tube, place one belt on the top tube with the "rough" underside facing you.
Wrapping around the top tube, insert the pointed end of the belt through the oblong hole ("bag slot") in the middle of the belt.
Pull the end through tight until it "catches" on the notches cut into the belt. This makes a secure loop that attaches to your top tube, the top of the "8".
Do the same with the second belt, so you have two belts on the top tube with buckles dangling below them.
Buckle one side and insert your bottle/cylindrical object. It's okay if it's a little loose right now, we'll come back and tighten it.
Buckle the second side tightly around the other end of your bottle to secure it. The first buckle is supporting the weight of the bottle so it is easier to really get a tight fit.
Now tighten down the first belt for a snug and secure fit.
Spread the belts toward each end of the thickest part of the bottle.
You can use these belts to carry any kind of cylindrical object, like an extra canteen of water on a long ride...
...or the Sunday Times to your neighborhood coffee shop.
You're all set to ride! Belts available for sale on Etsy and at walnutstudiolo.com. Cheers!