Features: High capacity and long endurances: 550mAh large capacity battery cell, single flight endurances increased by 30%. High magnification and strong power: Supports continuous discharge at 75C, with strong instantaneous power. Multiple safety protections: Equipped with a flame-retardant shell and intelligent protections board, overcharge, overdischarge, and shortcircuit protections, ensuring flight safety. Lightweight design: small size, reduces aircraft load, enhances flexibility, easily handles complex terrain crossing challenge. Multiple specification adaptation: 2S/3S/4S multiple voltages version is available, compatibility with mainstream time travel and model aircraft models in the market. Specifications: Material: lithium battery cell Type: 2S, 3S, 4S(optional) Capacity: 550mAh Size: approx. 67mm/2.63inch (more detail size please refer to pictures) Voltages: 2S(7.6V), 3S(11.4V), 4S(15.2V) Battery type: LiHV Charge port: XH2.54 Connection wire: XT30 with 16AWG silicone wire Package Includes: 2Pcs Lithium Batteries note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.