Hollis Mod-1 Full Face Mask BOV POD only The patented Kirby Morgan two-chamber (Mask & POD) design opens up multiple configuration possibilities with both Open Circuit and Closed Circuit Rebreather systems never before available. Switching gasses underwater or bailing out to an off-board system in the case of Rebreather use with the Hollis BOV Pod, is simple and straightforward because of the MOD-1's two chamber. Wireless or hardwired communications can be installed into the Mask and when communicating with other divers underwater or topside MOD-1 utilizes glass lenses instead of plastic, you can install custom-ground prescription lenses, a critical feature for underwater videographers and photographers to get that perfect shot, in perfect focus.