These 2-wire cables are 16cm long and come as a set. One side has a 2-pin JST SM type connector plug on the end. The other side has a matching 2-pin JST SM type receptacle connector. They are good for whenever you have 2 wires you want to be able to plug and unplug. We like the solid and compact nature of these connectors and the latch that keeps the cable from coming apart easily.