A converter that enables a 110Vac device (USA mains voltage) to be powered on a 240Vac mains outlet. Allows use of US electrical equipment with 2 or 3 pin plugs in the UK. Maximum Loan is 100W. Please Note: These transformers are not suitable for constant use and cannot be used for more than an hour at a time and they are not silent as they make a slight humming noise.