This is a ten foot Male/Male 1LINK cable that allows you to connect one 1LINK device to another. This is a perfect cable when you are using the Neptune Systems’ D?S— If you have a 1LINK connection free on your 1LINK module or Energy Bar 832, then you can toss the D?S Aquabus cable and the power supply aside and just use this single cable! Ultimately, this will help save time in wire management and you can spend more time with your aquarium and less time managing wires.