Important information about RFXtrx/rec firmware:

RFXtrx315 firmware can only be used in the RFXtrx315.

RFXrec433 firmware is only for the RFXrec433 receiver. 
If you flash an RFXtrx433 or RFXtrx433E transceiver with this firmware you will disable all transmit functionality in the transceiver!

RFXtrx433-Type1 and RFXtrx433-Type2 firmware will operate in the RFXtrx433 and RFXtrx433E.

RFXtrx433-Ext, RFXtrx433-Ext2 and RFXtrx433-Pro1 firmware will only operate in the RFXtrx433E.

RFXtrx433XL-ProXL1 firmware will only operate in the RFXtrx433XL.