This professional heating mat from Thermolux fits exactly into the greenhouse 39cm x 59cm! The heating mat is perfect for our conditions with the dimensions 30cm x 50cm. Not only do these heating mats fit perfectly with the greenhouses mentioned above, but they are also the right size for all cutting trays. Whether stone wool trays from any manufacturer such as Cultilene, Grodan or Speedgrow or cultivation trays from Eazy Plugs, thanks to this heat mat the chance of survival and more explosive root growth increases. It is best to cover the heating mat with a thin or thick layer of perlite, vermiculite or coconut, depending on your needs, to control the temperature well.