The SEA TOILET Portable Toilet is suitable for interior and exterior use. It is self-contained and it does not require any external water or power connections. It consists of two separate tanks: a fresh water holding tank of 12L capacity and a waste holding tank of 10L. However, you can change the waste tank’s capacity to 20L, by replacing the 10L waste tank with the 20lt waste tank (11869). The toilet is made of high-density polyethylene (HDP) with matte finish for greater resistance to scratches.