So on days you do not need a keyboard for your iPad Air, you could always detach it and leave it at home or in office and that reduces the overall weight. The case and the Bluetooth keyboard weights 380g and when you add in the weight of the iPad Air (Wi-Fi + Cellular), it totals to 858g.
In the pictures below, you will notice that the back of the VersaKeyboard (where it holds the detachable Bluetooth keyboard), there is a special rubber material being used to prevent scratches to your Bluetooth keyboard’s keys.
The Bluetooth keyboard contains full-size keys of a standard keyboard. The tactile feedback of the keys is a little soft for my liking. I think Logitech did a slightly better job with the tacticle feedback of the keys in the Logitech Ultrathin Keyboard Cover.
The Bluetooth range is 10m and the battery can last for 130 hours.
Detachable Bluetooth keyboard with 130 hours of battery life and LED power indicator
Folding VersaCover doubles as a stand in portrait and landscape modes
Ultra-thin and lightweight design
Durable polycarbonate shell includes convenient keyboard slot
Support for iPad auto-wake and sleep functionality