If your engine compartment lacks space for a 2nd battery, the Front Runner Power Box Battery holder is a convenient and versatile option to safely house the additional battery. A secondary battery can be used to power a fridge, auxiliary lights or other equipment that runs off 12V. The Power Box is supplied with a built-in and easy to read digital Volt meter to monitor the battery voltage and an Amp meter monitors the current drawn of any items connected to the Power Box. The Power Box accepts various battery sizes up to 105A and has an adjustable clamp to keep the battery secure inside the box. Maximum battery dimensions: 340mm (13.4) L x 175mm (6.9) W x 240mm (9.5) H. Can be mounted with a ratchet strap or bolted to any flat surface via 4 pre-existing holes in the base (hardware and strap not included). Use the channels to hold Black Tie Down Rings - by Front Runner (not included) for even more securing options. The front compartment accepts the following charger units: DCC Pro In-Vehicle DC-DC Battery Charger - by Intervolt, D250S Dual Battery Charger - by CTEK and DIY Split Charge System Kit - by National Luna. Suitable for your vehicle, trailer or camper. Made from steel and powder coated for protection. Extra socket panel inserts are available such as USB Socket Panel Insert, Merit Socket Panel Insert, Engel Socket Panel Insert and 12V Auxiliary Power Outlet Panel Insert. (sold separately) The socket panel module can be fitted to either the top, left or right-hand side of the Power Box. The socket panel module can be rotated and secured in 4 orientations on the side panels and 2 orientations on the top panel for ultimate flexibility. *NOTE: No cabling or connectors are supplied with this product. It is recommended that a qualified auto electrician handle all wiring requirements.