Mini Under Tank Heater For Hermit Carbs Reptiles Amphibians - Use with Glass Terrariums - Size Mini - 4 Inch x 5 Inch. Focuses heat to desired location and is an energy efficient low wattage external heat source. Excellent secondary heat source. Easy to install adhere directly to glass terrariums for maximum heat transfer. Other Blue Spotted Products to Consider: clamp lamps wire cage lamps heat emitters UVB lamps and mercury vapor lamps. Also consider Aquarium Masters airline tubing air stones