The PSG-JRBN40-FF is PSG series female to female jumper ribbons. These jumper ribbons are used for making wire harnesses or connecting between headers from one PCB to another. These premium jumper wires are 8" (200mm) long and come in a strip of 40 (4 pieces of each often rainbow colours). They have 0.1" header contacts on both ends and fit cleanly next to each. The best part is they come in a 40 pin ribbon cable. User can always pull the ribbon wires off to make individual jumpers or keep them together to make neatly organized wire harnesses.