M3B Plus Cart Size-Flexible Design with 3 Voltage Settings Battery capacity: 550mAh Dimensions: φ0.55 x 3.48 (in) / φ14 x 88.3H (mm) 3 voltage settings (2.8/3.2/3.6V) 10-second preheat Child-resistant lock Full metal housing LED indicator lights Compatible with 510 cartridges of any size Standard 510 thread Button activated USB-C charging