Description: Function: Gather the wire harnesses together, reasonably store the wires inside the car and ship, and is suitable for power systems such as cars, RVs, ships, and yachts. Design: Modular box design, used to resist rain and dust, resist air and seawater erosion. Performance: Removable side panels provide unobstructed routing in four directions and reasonably accommodate wires inside vehicles and boats. Stability: The battery terminal base is made of non slip sponge for added stability. Portable: Empty write space at the top makes it easy to add tags to each branch. Specification: Current: 300A Voltage: 12-48V Stud size: M8 M10 Material: Nylon, Copper   Size Chart: M10: 4.4cmx13.7cm/1.73inchx5.39inch M8: 5cmx13.8cm/1.97inchx5.43inch Package Includes: 1 Power Distribution Block 4 screws 4 screw 6 Gaskets Note: Please allow slightly errors due to manual measurement and different monitors.