3.7V 220mAh Replacement Battery Part Compatible with Haktoys HAK303, HAK321, HAK325, and HS365 Mini RC Helicopters Have extra play time! Optimum charge time: 2-3 hours, Run time: 8-10 minutes Compatible with Haktoys HAK303, HAK321, HAK325, and HS365 Mini RC Helicopters High-quality original replacement battery for HAK303, HAK321, HAK325, and HS365 Mini RC Helicopters Package contents: 1 x 3.7V 220mAh Battery Made of high-quality and non-toxic material. Safe and durable.