PHILIPS H33GL-400/DX 400W E39 Mogul 4200K Cool White Mercury Vapor Light Bulb

Philips H33GL-400/DX Mercury Vapor N 400W/542 CW Mog ED120, Ballast H33, Rated Life 24000 Hrs.Use Only with ANSI H33 Ballast Mercury Vapor lamps feature low initial cost, but have higher operating costs than HPS or Metal Halide due to its lower efficiency. The clear mercury bulb has a bluish green appearance and the Deluxe White has a higher color rendering. Mercury lamps get dimmer over time and rarely burn out, so it is wise to replace them and restore light level.

Manual:

Philips 248427 Mercury Vapor N 400W/542 CW Mog ED120