A neater/stronger stopper. Instead of tying a knot on the inside, you pass a line through and around the stopper to form a loop, finished with a splice or knot. The stopper always stays in place and cannot slide along the line. The stopper for 4mm rope has a 24mm diameter but other sizes can be printed such as the 5mm which has a 30mm diameter or 3mm (18mm diameter).

A stopper designed to work with two ends of elastic or cord. Can be made in a number of sizes - 4mm cord and 5mm cord are the most common. The 4mm stopper is 25mm wide and the 5mm stopper is just under 32mm wide.

Adding a stopper to an existing system that cannot be untied is not usually possible - but the broken stopper can be slid on without undoing anything. It is also helpful for lines tied tightly as knot can slide into the stopper from the side when tensioned. The 4mm stopper is 24mm wide and the 5mm stopper is just under 30mm wide.