Emergency Back Feed Cable, L14-30P to 14-50P Generator Cable 100ft
Generator Backfeed Cord for emergency power (4 prong to 3 prong) - YouTube
Dangers of Backfeeding & Safety Measures Against It
Amazon.com: VEVOR Generator Extension Cords 50Amp 75ft 125/250V, Backfeed Cord with NEMA SS2-50P to CS6364 Twist Lock, Generator to House Power Transfer Cord STW 6/3 + 8/1 for Outdoor,Trailer,Motorhome,Camper : Patio, Lawn