Carefull: even the grey ones exist in 2 non-compatible models:
ET 1050 and ET 1055
You can see which is compatible with which radio here:
http://etronix-rc.com/radio-gear/receivers
My local shop accidently sold me the wrong spare and I had to get it exchanged.
I have 2 of the grey ones, the type that works with the radio that has the LCD screen and multiple model memory.
Contact me if you're interested.