Range Rover Classic alarm sensor

Dear all does anyone know if all alarm sensors are the same as mine is probably knackered, there are several on the bay of evil but have different numbers. Also are they interchangeable with the P38 ones as they look the same, and is there any trickery in setting them up or are they plug and play.
Many thanks

Hi sorry don't know if they're all the same,think there's something about some have one circuit board and some 2 ,but they are supposed to be plug and play,no coding needed if that's any help

Thanks for that i will take mine off and look at the serial number.