1000W 400v DE Bulb 1000w - 400v DELumatek HPS Lamp 1000W DE 400V This Double Ended (DE) pulse start lamp, has been engineered for use with Lumatek 1000W Pro 400V electronic ballast and is produced using high grade ceramic arc tube technology and specific horticultural gas blend that creates optimal spectral output for healthy plant growth. Double ended HPS lamps are more stable than traditional, single ended HPS lamps and this allows them to have a 10% increase in light intensity and