Just hang the Curtain Driver onto the rail, and start enjoying automated control of your existing curtains based on weather, time, or other Aqara devices triggered. Up to 1-Year Battery Life*: Energy-saving technologies and a huge 6400 mAh battery make the Curtain Driver E1 apparently the most long-lasting controller of its type. You can forget about charging it for up to a year. Zigbee 3.0 Protocol: Enjoy the benefits of the fastest, most stable, and energy-efficient smart home technology. Better stability and compatibility (more standardized protocol), longer support, and more features.