Hi Vixen I'm currently gathering information on how to build a rebreather and one of the things I surely need is a simpel and yet reliable po2 monitoring. Thats when I came across your posts "2 Cell PO2 Display with HUD ..." If you are interested I would like to purchase a set of documentation containing pcb-layout, schematic, BOM and function description to built my own copy of your design. Would you be interested and what would you be asking for such? Best regards Sebastian A hopfull to be RB diver