Due to its sealing performance, the Fischer Freedom™ Series is the ideal connectivity solution for extreme environments. A small pH indicator paper is placed between the plug and receptacle. The connectors are mated and then immersed in water inside a pressure vessel at 2 bars, which corresponds to an immersion depth of 20 meters. After 24 hours of continuous immersion, the connectors are removed from the pressure vessel and unmated. No color change can be seen on the pH indicator paper, which indicates that no water has penetrated the connector housings.