The Flat 2.0 Series is a premium, high-capacity 510-thread battery designed for durability and extended use. Featuring a square stainless-steel body to prevent rolling, it delivers precise performance with an OLED display and fast USB Type-C charging. Features: • 401 mAh high-capacity battery (?1.0 h Type-C charging time) • Size(mm): 14*14*80 • OLED display showing battery, voltage, resistance, and puff time • Adjustable voltage: 1.8V–4.2V • 10-second preheat at 1.8V for smooth vapor • Built-in puff counter and smart safety protections • Auto shut-down after 1.0 hour of inactivity • Universal 510-thread compatibility