With the KnotBone Cord Lock you can securely tighten the drawstring of any article of clothing, rucksack, satchel or bag to just the right tension. Simply thread both ends of your cord through the KnotBone Cord Lock’s closed end, one at the time, pull to the desired tension and wrap to lock. Available in a pack of four Cord Lock #3s Fits 2.5mm diameter cord Simple to use: Tighten, Wrap and Lock Use two ways: Lock & Go or Cinch & Go Single part design—no moving parts or springs