This is a light weight, high energy density polymer lithium battery. It outputs a nominal 3.7v at 980mAh, including built-in protection against over voltage, over current, and minimum voltage. It comes terminated with a standard 2-pin JST connector-2.54 mm spacing between pins.
Please do not attempt to charge these with anything but a specialized Lithium Polymer charger.
This is a splittable 40 pin jumper wire, it is super flexible, can be transformed from 1-40 pin jumper wire. With some of these, you will no need to worry about the jumper wires you got before do not fit your project, just split it and go.