How to attach the locking strap to the watch
What's in this video?
Yes, please follow this link to purchase extra keys.
Yes, it just needs to be a watch strap that uses a pin mechanism and a width that is a maximum width of 22mm.
Changing the watch strap is the same as a typical watch, by pushing in the strap pin (with something thin like a paper clip) via the pin holes on the side of the watch chassis.