Plugs into occupied or vacant energized fuse block slot. Protects original circuit and provides lead for a new circuit for mini fuses include fuse 2. This high quality Add a circuit/fuse Kit allows easy installation of additional circuits without cutting or spicing. 3. Turn one fuse slot into two while providing protection for both circuits. 4. This Dual slot add-a-circuit/add-a-line/fuse plug provides a fuse slot for the existing OEM circuit and a second slot for a new circuit for a mobile electronic devices/accessories such as a mobile phone, radio, mobile accessories, etc.