It's used on the head, to create a lightweight body, to segment up the body of big streamers and hold open materials, creating volume while being lightweight, making it easy to cast all day.

The 10 mm diameter version is best suited for creating a small "collar" that keeps the materials spread out, allowing them to push out more water and have the illusion of volume, and for creating a bulky but light streamer body.

Tips for use and videos here: www.sybai.com/bodyflex