Ideal heater to keep the greenhouse warm through the night and prevent frost from building up. The heater comes with a 4.5L tank so it is enough to burn for 40 hours or so depending on how big the flame you set is. It has an adjustable wick and tall chimney as well as a secure tank so no leakages happen. This heater comes with 2 wicks so you can burn more paraffin thus generating more heat for larger greenhouses. A little assembly is required with full instructions provided.