1LINK is the marrying of the Aquabus communication standard, along with the power wires to drive higher power devices, all in one single cable. One of the benefits of this is to avoid the need for a DC power brick for every 24V device in your aquarium. The cables are available in two varieties:
1LINK Extension Cable- 10' Male/Female Cable that can be used to extend a M/M cable.
NOTE: No single run of you 1LINK cables can be longer than 20'.