Review on Ravenox Strong Barreloc Cord Locks for Drawstrings, Rope, and 1/4-Inch Cords - Ideal Cord Locks for Strings, Bags, Twine, and Outdoor Activities - Bungee Cord Ends for Improved Durability by Amy Mcleod

These are quality cord locks at a great price. The brand I have is Fastex. The hole is approximately 15/64 inch, 0.234 inch, 6 mm in diameter. The inner part has a slight bulge in the middle, which increases the holding power and slightly reduces the cross-sectional area of the hole. I found an old Fastex cord lock of the same size that I have fitted to some jogging pants that does not have this grommet on the inside and has much less holding power than this new design. The force required to fully open the lock is approximately 9 pounds. The best tool I've found for threading cotton cord through the hole is a crochet hook (Susan Bates, size G6, 4mm).