I was replacing some lamps and i realized our lamp place sent us HMI 705, which is a 700W single ended HMI lamp. It looks just like the S/A. I then asked the person who ordered them whats up with these and they told me that they were told by the supplier that they would work and they were about 30 bucks cheaper. So i figured what the heck, and threw one into a test fixture and it fired up and ran for a good hour with no explosion. But before actually replacing my rental unit lamps with HMI's what is the difference? The strike voltage and operating voltages were the same. I know ship will have an answer. I am guessing a color temp difference?