Hi ya Klunk
The Electronize speed controller type 43VR is the one with BEC - it should have an orange and red cable coming out of the size as well as the standard red, black power supply - blue and yellow to the motor and obviously the connection to the Receiver. The switcher on top had me baffled for a min
but you are referring to the relay - there also should be a speed range hole and a neutral setting hole for you to set the appropriate ranges.
The Type 43X is exactly the same, only, it doesn't have the BEC - so therefore there should be no orange and red wires coming from the side. Everything else is exactly the same; you are right I presume it is a 15 amp - however, just to be on the safeside - I am going to go through my 'old' electrical documents to check for you - I believe they did do a 10 amp one - but I cant remember.....