Efficient power adaptation: - Enables operation of multiple devices with high efficiency by converting DC from 21V tool batteries to 220V AC. Supports second use of cordless tool packs for outdoor and indoor use with reliable 21V to 220V transformation. Versatile application: - Designed for multi device compatibility with AC and USB charging options. Charges two devices simultaneously and expands usable scenarios across different environments. Dynamic power regulation: - Smart adaptive system with dynamic output calibration automatically detects input power. Prevents overload, stabilizes output voltage, and contributes to long term battery durability. Stable output: - Backed by a multi layer protection circuit for reliable current delivery. Safe operation through effective reduction of voltage fluctuations and efficient, quiet conversion. Use scenarios: - On a job site or at home: power a cordless tool battery while charging a phone or tablet at the same time. - Outdoor activities: run a small AC device such as a fan or light using a 21V tool battery and simultaneously charge USB devices. - Home or travel use: provide stable AC power to two devices in environments where access to conventional outlets is limited, using existing tool batteries.