For over 90 years we have been supplying manufacturers with small supporting products, snaps, zippers, drawcord, cord locks, and dozens of other items that are small but important to complete your project.
It's a double spring loaded barrel cord lock that gives bags, hoodies, clothing, etc. even more adjustments with a quicker tension release on either side.
When it's squeezed together, tension is released and the cord lock can move freely up and down the cord. When released, tension is engaged and the cord lock stays in place.
These are great for use on sweat pants or hoodies to keep from losing the drawstring and to tighten the drawstring as well.