To give baggage handling systems zero chance of taking it off, it is equipped with an extremely sturdy and fortified strap. This does mean that it might take a bit of effort to detach the device from your bag. Especially for the first few uses, it takes a bit more work as the system is still new.
The most important steps when detaching the Flex are:
1. Firmly press the pin, in an upward position, in the hole of the strap case.
2. Pull the Flex away from the baggage handle while pressing the pin into the hole.
3. Further loosen the strap on the back of the Flex to detach the device.