The Ooze USB Smart Charger comes in a display tub of 30 units and is compatible with all 510-thread vape pen batteries. It features overcharge protection, automatically cutting off power once the battery is fully charged to prevent overheating and extend battery life. The charger uses a red-to-green light indicator to show charging status, making it easy to track when your vape pen is fully charged. Designed for portability, the charger is compact enough to carry in your pocket. Ooze requires using this charger with their vape pens to maintain the device's warranty.