I've checked voltages on pars til I am blue in the face. It's easy, just flip it over. I've run them yellowish 10.0 to whiter 11.5. I've tried the xelogen, halogen, GE, who cares what you pay, 12 bucks, 20 bucks, and cheapie china ones. I gave up years ago. I'll repeat, great floody beam, MR's can't touch that, but too much leaf/debris and bulb service.