This Blue 16 Amp Male connector is a single phase connector that is commonly found on UK & European Campsites and Marinas. This adapter would typically be used to convert your camping/ caravan trailing orange hook up cable from a Female 16 Amp IEC 60309 Socket to a UK Mains 3 Pin 13 Amp Socket or to convert the power output from a generator to UK standard 13 Amp Mains Socket. Though the 16 Amp connector is waterproof to IP44, the UK Mains Socket is not, and as such should only be used indoors in a dry environment.