This is an ideal ultrasonic for the hobbyist due to its price it's not as powerful as a professional unit it just takes longer to work. THE INSTRUCTIONS SAY THE MACHINE MUST BE EARTHED. THE LEAD SUPPLIED FOR THE UK HAS AN ADAPTOR THAT GIVES NO EARTH CONNECTION .This is a safety issue as the machine is all metal and filled with liquid. Get an adaptor that connects all three pins or cut off the plug supplied and put on a UK one with a 5 amp fuse. The other option is to find a lead with the appropriate plug on it.