Amazon.com: (3pcs) Matek Micro BEC 6-30V to 5V/9V Adjustable Step-Down Regulator for 4/5 inch 220mm 210mm 250mm 6s Carbon Fiber FPV Racing Quad Frame X Quadcopter Like Martian II 220 QAV250 QAV210
RTF Power Distribution Board with 5V BEC
Hobbywing 3A Switch Mode UBEC 5V 6V Max 5A Lowest RF Noise US - HeliBatics.com