This 2018 Promaster 159 custom build was for a simple RV. Basic package with walls, ceiling & floor complete, no plumbing or appliances. We installed 2 conventional slider windows, night shades. Customer wanted twin beds with lots of storage. We installed 16 feet of custom cabinetry & AC, Maxx Air power roof vent and our electrical package, including 2 AGM batteries and the 2000 watt pure sine inverter with 80 charging system!