The Thetford Porta Potti 345 is the original and best portable toilet! It features a refreshed, modern appearance and industry-leading performance with an exclusive rotating pour-out spout. The ergonomic carrying handle makes transporting the Porta Potti 345 easy. Fresh Water Capacity: 4. 0 gallons. Waste Water Capacity: 3. 2 gallons. Average Flushes: 33. Dimensions: 13" height x 15" width x 16. 8" depth.