The 200 watt submersible heater combines quality construction techniques with durable parts to provide a complete solution to any terrariums heating requirements. Just throw it in some water and turn it on and it works great. Heats up to 100 F. The check valve filter will ensure clean air is being supplied to your terrarium and the digital thermometer will allow you to monitor the temperature inside your grow chamber and incubator. All of this combined with the air pump & the Tropic Aire humidifier gives you all the necessary components to assemble your own mushroom growing system and maintain the correct variables to have a successful grow.