Rain Bird - WR2-RFC - Wireless Rain/Freeze Sensor Complete Kit

I have an esp13 rainbird controller is this rain senor conpatible?

Are there replament discs since wr2 disk assembly - #637810s is no longer available even though the manufacture still sells this rain sensor (??!!)

Mine is sst-600in, does it work with this model? i can directly connect the sensor to it or i need to buy a transformer?

What is the difference between the 553000 & 553100?