Overall height of the body was 10.5 metres (of which most was submerged), surmounted by a mast and extendible aerial of 9 metres. Data (air and water temperature, atmospheric pressure and relative humidity) were encoded and transmitted four times a day. When the batteries (high voltage dry-cells for the valves, and nickel-iron for other power and to raise and lower the aerial mast) were exhausted, after about eight to ten weeks, the unit self-destructed.[3][4]