I've purchased from Wilcox several years ago. It was a white light system for the HK MK23. The quality is top notch. It's not as bright as a Surefire light. I don't know much about the AR15 system. This company sells their products.
www.cfi.com I bought mine derect from wilcox. They had great customer service. You might want to post this question to the guys at ar15.com.