philw be very very carefull when wiring it up! there is absolutely NO REVERSE POLARITY PROTECTION. it smokes real easy :-( when it worked it was great.

philw @Geoff comparethe size of the box to the size of the inverter, there appears to be plenty of room for padding , either there wasnt any put in or the postal service dropped something heavy on it, which is most likely. to bentd the metal like that it would take a big force. more than you would expect in normal handling. so i dont think banggood are to blame for this one.

philw initiallyI thought the same ! but adjusting the blue variable resistor is what you need to do otherwise yes vin = vout.