Think the two button one is needed for the alarm.
As the little button dead lock it.
I think both type keys can be synced as long as it infra red.
you can see if the key is working by getting a camera and looking at the sender.
Phase 2 keys have a transponder thingy in it for the immobiliser to start the car.
Not sure if you can re-sync this to another car.
Phase 1 keys don't as they have a key pad.
As the little button dead lock it.
I think both type keys can be synced as long as it infra red.
you can see if the key is working by getting a camera and looking at the sender.
Phase 2 keys have a transponder thingy in it for the immobiliser to start the car.
Not sure if you can re-sync this to another car.
Phase 1 keys don't as they have a key pad.