The Streamlight 66321 Lithium ion Battery is the perfect accessory for your Streamlight Macro Stream USB flashlight. This rechargeable battery provides up to 4 hours of continuous use on high mode, making it ideal for extended periods of use. With the ability to be recharged up to 500 times, this battery offers long-lasting performance and is a cost-effective alternative to disposable batteries. The LED indicator light displays the battery level and charging status, so you always know when it's time to recharge. The compact and lightweight design makes it easy to carry with you wherever you go, and the durable construction ensures it can withstand the rigors of daily use. Whether you're a professional in need of reliable lighting or an outdoor enthusiast looking for a dependable power source, the Streamlight 66321 Lithium ion Battery is the perfect choice.