These custom-made wooden covers are manufactured in thermowood finished with stainless steel. The design matches the look of the stock tanks perfectly. The covers are made to keep leaves and other debris out of the stock tank. Because the cover is not completely closed, a natural circulation remains so that no fungi can form. The cover is also made to better insulate the tank so that the water stays warm longer or heats up faster when heated. You can order these in the different sizes. So that it is perfect for your tank.This is foldable so that you do not always have to open the tank completely and can enjoy an extra lounge feeling.