Retevis Two Way Radio Battery 1000mAh Replacement Battery Compatible Baofeng BF-888S 777S 666S Retevis H-777 2 Way Radio(2 Pack) Original replacement rechargeable 3.7V 1000mAh Li-ion battery; easy to set up on radios and fit well Compact and lightweight; Great for outdoor activities with measures 50*15*85 mm when your radios out of power Suitable for Baofeng BF-888S BF-777S BF-666S Retivies H-777 Walkie Talkies The fantasticbattery is durable; works right in charging unit; keeps the charge for nearly 36 hrs Worry Free Warranty; We offer 60 days warranty and 30 days no reason to return service with our friendly and profession customer service team