10pcs Black Toggles for Drawstrings & Shoelaces, Plastic Cord Adjusters with Single Hole Spring Locks for Clothing, Backpack & Luggage

The grip is good, strong

Well made with no sharp edges or projections. So suitable for use on kiddies clothing and accessories as well as adults.The description says up to 7mm cords. Fully opened the aperture is oval and measures about 6mm at the widest point and about 5mm high. So a 7mm diameter circular cord is going to be a tight fit but smaller paracord or string will be fine. Hence the one star lost.Spring is quite strong and operation is smooth. The pull through force will obviously depend upon the roughness of the cord or cords passing through the clamp.

A lot smaller than I expected, the photos say go on different things like backpacks etcYou’ll be lucky to get a piece of wool through these

Not a great amount one can say - these will accommodate up to (say) walking boot lace/normal paracord widths, have a good spring in them, and are small and neat.Very useful in a range of non-safety critical applications; happy.