OPXS has another Patent Pending for a M17 M17 DAY/THERMAL (DT) unit is a direct replacement for a standard M17 periscope and enables 24 hour situational awareness by utilizing two cameras and an 6.5” display. M17 DT unit mounts directly into existing sites intended for an M17 standard periscope. Both cameras are located within the main housing of the M17 DT unit while the display is located on the viewing end of the mount where the exiting image would normally be located on the M17 periscope http://www.optexsys.com/spec/M17DT_Datasheet.pdf