The L401 is a natural-colored LDPE plastic 20-410 ribbed skirt pre-drilled yorker spout with red tip with pressure sensitive (PS) liner (0.03 inch orifice). A yorker spout is a conical-shaped closure with a small cap on the tip. This yorker spout has been pre-drilled. To dispense product, the tip cap must be removed. The tip cap is then put back on the spout to preserve product. This cap comes with a pressure sensitive (PS) liner. Pressure sensitive liners are made from foamed polystyrene. When the cap (with liner installed) is affixed to the bottle, the liner adheres to the bottle's landing/orifice. Before product can be dispensed, the lid must be removed and the PS liner peeled off and discarded. This lid is made of LDPE, a highly flexible plastic with high heat tolerance levels. This closure fits a container with a 20-410 neck finish. The first number refers to the diameter of the container's opening (in mm). The second number refers to the thread/style/depth of the closure's skirt. Please read 5 seals and how they make perfect liners for your container for more information on liner types.