Rapid Links are a zinc plated steel link with a nut on one side that when unscrewed creates an opening. The size of the opening is approxiamtely the same size as the stock diameter of the link itself. Our Climbing/Swing Ropes have a 3/8" or 1/2" pear shaped sling link at the top which would fit into a 1/2" rapid link. Our nets have various size rope borders depending on which net you purchase; these would need a larger rapid link such as 9/16" or 5/8". The rapid link opening isn't large enough for 3/4" and 1" rope but with a little patience you can manover the rope onto the rapid link since rope has give to it. You can also order the rapid links when you order your net and we can install them on the net when it is being constructed. Simply add the instructions to your contact form when ordering. Combo Rope Ladders have a 5/8" thimble/s which require a 5/8" rapid link. Once again we can install the rapid link/s on your ladder when we construct it if you would like. Rapid Links are made in China.