The Dometic M65-700 marine toilet is a complete toilet and holding tank system in one package. This Type III MSD has a 6.5 gal. (24.6 l) tank and makes a great replacement for permanently installed portable toilets. Pedal flush method. Low-flush water consumption: less than one pint (0.10 gal/0.39l) per flush. 1-1/2″ discharge fitting. Standard plastic seat.