The Dual 18650 Battery Holder Box with ON/OFF Switch is a rugged, compact power storage solution designed to house two 18650 lithium-ion batteries. Engineered with high-quality, impact-resistant ABS plastic, this 2-slot enclosure features a built-in tactile slide switch that allows you to instantly control power cut-off without disconnecting your wires. It comes pre-wired with color-coded positive (red) and negative (black) flying leads for quick, hassle-free integration. Equipped with premium nickel-plated steel retention springs for reliable contact, it provides a stable 3.7V (parallel) or 7.4V (series configuration) power source for Arduino microcontrollers, robotics, RC vehicles, and portable DIY electronic devices.