Schluter® KERDI-DRAIN PVC HORIZ OUTLET - WITH CORNERS/SEALSThe KERDI DRAIN PVC horizontal outlet body with pre formed corner seals included everything you need for the drain rough in when you're working on a concrete slab and can't use a vertical drain connection. Most residential showers drain straight down through a vertical outlet. Horizontal outlets exist for slab on grade construction (basement showers, ground floor slabs with no access below), renovations where the vertical drain stack can't be