Sola E-SZA00W100 - 100 Watt - 120-277 Volt - HPS Ballast | CityLightsUSA.com
Lighting-Gallery.net - Elmer's Low Pressure Sodium Lights/Ballast and Socket for 18W LPS Lamp
Ben Krasnow on Twitter: "You can still buy low pressure sodium lamps (eg on Amazon), but the ballasts are expensive and rare. I found that using a cheap CFL ballast, and replacing
Universal Core and Coil Ballast Kit For 1000W High Pressure Sodium Lamp 120V-480V | S1000ML5AC5M500K | Bulbs.com