AC WORKS NEMA 14-30P to NEMA L6-30R 30-Amp 4-wire To 3-wire Grounding Single To Single Orange Basic Elbow Adapter in the Adapters & Splitters department at Lowes.com
GE Polarized Grounding Outlet Extender, 2 Pack, Turn 2-Prong into 3, Easy to Install, Indoor, UL Listed, Gray, 54302 - Power Strips And Multi Outlets - Amazon.com
2 Pack ETL Listed 3 Prong to 2 Prong Adapter, JACKYLED Polarized Grounding Converter 3-Prong Adapter Converter Fireproof Material 392℉ Resistant Heavy Duty for Wall Outlets, Electrical, Household - Amazon.com
Three Way Grounded Adapter
H-E-B 3 to 2 Grounded Adapters - Shop Extension Cords at H-E-B
Fundamentals of Electricity
AC 3-Prong / Pole Ground Lift Grounding Plug Adapter
4 Set 3 Prong to 2 Prong Outlet Electrical Ground AC Adapter Grounding Converter - Walmart.com
Complete Home Grounding Adapters White | Walgreens
Commercial Electric 15 Amp Single Outlet Grounding Adapter, Gray U-09 - The Home Depot