This is Hobbywing's latest motor, the mighty G4R. this is quite possibly, the best bang for buck motor and the best performing motor on the market today! the EFRA spec motor comes WITHOUT the epoxy heat paste Whilst the ROAR spec motor has the epoxy heat dissipating paste around the windings. This makes the EFRA motor lighter than the ROAR edition motor by approx. 4.5grams. ROAR motor rules will make the epoxy based motors illegal from September 2026, so please shop with this in mind. Generally speaking, the ROAR motor copes better with dissipation of heat due to the use of the heat paste yet both motors perform identical in regards to power and torque output with any performance variances between the two being manufacturing based micro tolerance differences that you will find across both the EFRA and ROAR series. Manufacturing tolerance differences are common across all motors on the market today.