Please install slip parts assemble. Don't install motor to track until you can operate track smoothly manual. Otherwise belt May be destroyed. 3M track or less, like 2.9M, 2.8M. You can order directly and leave message to.Tell us the correct length you need. U type or Ltype curtain track. Please also let us know, we can customize. Xiaomi aqara /Dooya KT82/DT82 TN/TV/LE. The item "3M Xiaomi Aqara Curtain Rails, Zigbee Wifi work with MI HOME, smart remote control" is in sale since Monday, April 8, 2019. This item is in the category "Consumer Electronics\Surveillance & Smart Home Electronics\Other Smart Home Electronics". The seller is "supergreenlight" and is located in Hok Tsui Tsuen . This item can be shipped worldwide.