This is Alligator Clips Electrical DIY Test Leads 10pcs of Double-ended Crocodile Clips Roach Clip. It is insulation covered clips connected to the wire from both ends.
It is useful in electrical or laboratory electric testing work. Alligator clips are frequent use in school physics laboratories to quickly and cheaply assemble circuits. They are very useful for connecting components to wires.
Alligator clips can also be used as miniature clamps to hold parts together. In addition, it is also useful for gluing and wires together for soldering. Easy for installation and safety for use with the insulation red soft plastic insulation cover.