Grodan's RW101701 Pargro Quick Drain slabs are considered drier slabs due to its rockwool fibers. It allows for fast drainage through horizontally run fibers. This slab measures 36 x 6 x 3 inches, making it particularly good for growing large vine crops such as tomatoes or cucumbers. For plants growing outdoors during mid-day sun, Quick Drain slabs provide a good water buffer. Hand water or use with drippers or in Ebb and Flow (Flood) systems. Instructions and illustrations are printed right on the packaging for convenience. Case contains 12 slabs.