I purchased a Mars MW from a private seller, it has a 320x256 MCT (Mercury Cadmium Telluride) cooled sensor. It outputs 350hz analog video. It sees in 3.7um to 4.8um. Depending on the lens you use on the sensor it can vary from 30-20mK at a 30um pixel pitch. I believe my unit was ripped from a IRC-HY8000, which I believe was built by Guide using French, Swiss, Israeli, etc. It does function and takes about 6 minutes to cool down fully to operating temp at 70k.