This is a 30 cm servo extension cable.
This comes in very handy when your servo is further away from the controller than the wire on the servo allows.
Male connector on one end goes to controller, female connector mates with servo.
Fits all Hitec, Futaba, JR, Multiplex, and Airtronics Z servos.
Wire can also be used as a simple 2,54 mm jumper cable.

 

Note: These wires have a weird naming convention.
Both ends of this wire have what, in most cases, should be called a female connector; but, for these wires, the presence (or lack thereof) of the plastic shroud is what makes an end female or male.
If you're looking to plug one end of these wires into a breadboard, you could stick our breakaway male headers into the un-shrouded end to make it a true male connector.