Camco 55623 RV 50' 50-Amp Male and 50-Amp Female PowerGrip Marine Locking Extension Power Cord - Walmart.com
Amazon.com: RVMATE 50 Amp 25 Feet RV/Generator Lockable Power Extension Cord, Easy Plug in Handle, 14-50P to SS 2-50R with LED Indicator, ETL Listed : Patio, Lawn & Garden