Advanced Drainage Systems Polyethylene Locking Sump Liner Lid will keep your sump safe. This lid has a one-piece mold design and is made of robust and lightweight HDPE. It fits the ADS sump well liner and secures with a partial turn for safety. Self-tapping screws, knockouts, discharges, power lines, and vents can all be housed in this locking sump lid. It keeps dirt, children, and pets out of your sump pump.