6-inch flat square grates connects to 3 & 4" S&D Hub, and Drain Pipe and Fittings, Triple Wall Pipe, and Corrugated Pipe. They are ideal for planter beds, mulch areas, window wells, and areas prone to debris collection. This grate helps to collect and remove excess water from driveways, patios, yards, and any other outdoor areas. ADA-compliant, designed for maximum strength and durability, StormDrain Water Management Systems grates feature UV inhibitors that prevent fading and cracking from the sun. These chemical-resistant and rustproof grates are maintenance-free, lightweight, and easy to install.