Price reduced to £17!!! Still selling for £37.98 at Tesco Direct.
Catalogue number: 203-8659http://direct.tesco.com/q/R.203-8659.aspx
Found this at my local Tesco Store (London, Seven Sisters branch)
OWL Wireless Electricity Monitor is the original, wireless electricity monitor. It's designed to help you save money, electricity and the environment. OWL now features a NEW cumulative memory function making it easier than ever to monitor electricity usage.
OWL comprises three elements:- the sensor, the transmitter and the display unit. Installation is safe, quick and easy, with no electrical knowledge required. Batteries are included.