A standard domestic one but with lower wattage than you would buy for a house. The “ dedicated” leisure ones are over priced and not that reliable. Bear in mind the current rating of your electric hook up. Power = volts x amps. So if you divide power by volts (240) you can get an idea of amps. Cannot remember precisely what make we last used, but it came from Argos. Think it was around 1 kw as a travel kettle.