FMA Tactical Functional GSGM NVG Mount Helmet Mount BK/DE. That showing the effect of matching products. Matching: there are three different bases which can be used together. Description: GSGM is a functional support, using a CR123A battery can only use > 3V battery, can not use. The images shown are not the actual item and are for your reference only. SERVICE TRANSIT TIME is provided by the carrier and excludes weekends and holidays. Transit times may vary, particularly during the holiday season. If you need to return, please contact our customer service representative, let us ...