I got tired of using the vial I purchased my my local home brew shop. It used far too much beer to get the hydrometer to float. Once I tried using the tube that the hydrometer came in. Unfortunately it tipped over and broke the hydrometer. Here is my solution.

This one is pretty simple, 0 shells, 10% infill.

The hydrometer is a Triple Scale Beer and Wine hydrometer purchased from Brew and Grow. There's no brand name listed. The tube has a 27 mm diameter.