The Sun-Mar Centrex 1000 is ideal for light to medium seasonal use. It is specially designed for narrow spaces, being only 22.5 in. wide. The Centrex 1000 is an electric unit for those with a constant electric supply. All Sun-Mar composting toilets incorporate a patented Bio-drum which ensures fast and odorless decomposition. Saves thousands of gallons of water, while recycling waste into soil. The unit is shipped fully assembled. A one pint flush toilet is required for use with this unit (sold separately). Seasonal capacity: 5 adults or families of 7. An optional dual electric and non-electric configuration is available for this system. It requires the separate purchase of the Sun-Mar AC/DC kit.