Vivarium Heating Mat British made, 1mm thick flexible heaters. Can be used beneath or on the side of tanks. Only 50% of the surface area should be covered. Under normal usage a thermostat is not required. All 240 volts complete with fitted plug. 10cm x 13cm ( 4" X 5") - 4 watts
Google is brilliant for bug information and photos, just search on the scientific name (common names may vary). Don't limit your search to the UK as much of the information comes from the USA and Europe.