SD Slot Drain Product Description The original Slot Drain is one of the first Stormtech products. It has a 25mm opening on the top with 20 slots draining into a 90mm drain pipe. The Slot Drain is used for stormwater run-off and also suitable for surface water drainage around garages, driveways, paths, pedestrian and paved areas, courtyards, sporting areas or garden edges.Product Applications DrivewaysThresholds and DoortracksPools and Paved Areas Patios, Courtyards and Terraces Commercial Applications and Large Scale Projects Special Needs Access