Leviton 15 Amp White Medium Base Lamp Holder Outlet Adapter - On Sale - Overstock - 11846490
Leviton 30 Incandescent Lampholder, Medium Base, Two Piece Porcelain; 660W-600V; Keyless; with Two 8-32 By 1/2 Inch Long Mounting Screws. - Light Sockets - Amazon.com
Leviton 600-Watt 250-Volt White Outlet Box Lampholder R50-49875-000 - The Home Depot
Leviton 3-Way Socket Lamp Holder R50-07090-0PG - The Home Depot