1. Compatibility: The USB to 2.5mm DC cable is compatible with devices with a round 2.5mm DC charging port, including massagers, toys and other electronic devices with USB power. Whether you're replacing a lost cable or upgrading your charging system, this cable works seamlessly with a variety of devices. This package contains 2 USB 5V DC charging cables for versatile use. 2. Functions: The white cables are 1 m long and have a diameter of 2.5 mm. This DC charging cable with pure copper core is extremely durable and provides , reliable charging performance for your devices. 3. Easy to use: Charge conveniently via any USB port, whether it be a wall charger, power bank, laptop/PC or car charger ideal for fast and versatile charging. 4. Connector Type: USB Male to Mono Headphone Jack with 2.5mm diameter (16mm length). Charging time varies by adapter; 5V 1A USB chargers are recommended, while 5V 2A chargers allow faster charging.