I don’t want to speak for Teth-Air; but in short it is a leashless tether. I believe low power RF transmitter is worn and a receiver is mounted on the sled, if they loose communication with each other the reciever assumes you are no longer in control of the sled and instigates the shut down.
Feel free to correct any of my assumptions. I can edit or delete this as appropriate.
Okay
So for a sled with NO tether, this would be a great addition.
But for a sled with a built in tether, is this just for the convenience of NOT having to clip in when you get ON or OFF the sled?