We are using Cree LED chips, with standard efficiency at least 110lm/W. Other brands can also be used. Our LED tunnel lights are designed for a life time of at least 50,000hours with many interesting options: DALI communication or 1-10V dimming or autonomous system of dimming. They can replace traditional HPS light with excellent features like long life time, high luminous efficacy, clear comfortable light and reduces environmental pollution. They work with AC100-240V directly. CE RoHS approved