The OEMTOOLS 4V Max.* Li-ion Cordless Screwdriver is used for fastening and pre-drilling wood, plastic and light-gauge metal, and other applications. The screwdriver uses a high-capacity, 4V Li-ion slide battery for longer life and more power to get the job done. The trigger activated LED work light is perfect for jobs with minimal lighting. The battery resists self-discharge and will remain ready-to-use even after storage. The charger is designed with an auto shut-off feature to save energy, prevent over-charge, and enhance battery life.