The FATHOM Heads Up Display (HUD) utilizes a modified Smither’s code to display current PO2 information.  Designed as an add-on for analog CCRs, the electronics and battery are housed in a surprisingly small 1.5” diameter x 3” long cylindrical housing.  On startup, the HUD indicates battery voltage through a series of flashes.  The ½ AA SAFT battery lasts for 200+ hours due to the surprisingly low power consumption.  The LED display is reversible so can be worn on the right or left side while keeping proper left to right cell orientation and is light sensitive so automatically adjusts to ambient light conditions.  The HUD is available with a Fischer connector, AK 4-pin connector, or an unterminated cable for hard-wiring into your CCR’s head.