I have Thetford 92360 Porta Potti
portable toilet and it is one of the best one on the market . The waste capacity is 5.5 gallons with a fresh water reservoir of 4 gallons. The flush system, which is sufficient for about 55 flushes, is a battery, operated via a button. The seat is designed for comfort so the overall height is a little higher than some portable toilets. The toilet has an integrated toilet roll holder. To empty, there is a large capacity spout that, when empty, is sealed off with a cap.