100W 250W 400W High Pressure Sodium Lamp Ballast Magnetic Ballast HPS Ballast - China High Pressure Sodim Lamp Ballast, Magnetic Ballast | Made-in-China.com
High Pressure Sodium Lamps – Basic Lighting for Electricians: Level 2
Advance 71A7971-001D - High Pressure Sodium Ballast - 70W | Energy Avenue