This is the plastic tube typically included with our standard lock pick set and certain other tools. We have extra and sometimes customers like to have a few spares, as well, to better manage and store their equipment. While it may not be worth it to purchase a single one of these from us by itself, some folk opt to add them to larger orders so that they can keep things organized in their field kits.
This plastic tube is made of clear-ish semi-transparent High Density Poly Ethylene and has an interior size of about 15mm x 15mm. It can expand out to approximately 220mm or compress down to 125mm, more or less. Some people like to use these tubes to hold a traveler hook so it doesn't snag or poke other things in a tool bag.