Trenkle German Black Forest weather house made of plastic, weatherproof TU 891 Colour: Coloured Height: 12 cm/4,8 inch The weatherhouse is made of plastic and weatherproof. This is how a weather house works: There is a gut string inside, which reacts to all changes in the air humidity. Depending on whether the air is dry or humid, the gut string changes its position and twists more or less, so that the female turns outside when it is dry and the male, when it is humid.