This 1000 watt SolarMax™ 1-Dual Arc Tube Lamp Burns MH & HPS In One Lamp. It runs a 400 MH and a 600 HPS in one lamp allowing you to get the full light spectrum for your plants. This SolarMax Grow bulb takes a 1000w HPS ballast to run. This bulb puts out 100,000 Lumens.

Glass size: T-23