34 1/2″ x 20 5/8″. 10 1/2″ shower pan depth. Comes with 3″ ABS plastic drain flange for the tank dump (separately, not installed). Has 2″ drain in the shower pan and 2″ vent for tank. The holding tank is approximately 10 1/2 gallons. Perfect for Transvan and Casita models, and also van conversions and skoolies.