ERP= engine replacement program....which means you can replace your engine for less money (I think they are like 1/2 price)...whether you just want a different one or your old one is ruined....Eddie offered you to use the himoto ERP and thats a hell of a deal

failsafe is just incase your reciever loses transmission from the transmitter...you adjust it so it applies the brakes when and if it should ever happen...this will help protect your rc running off on you (taking off and you have no control)

you can get these from Eddie