The L027BK is a black metal 70-400 continuous thread cap with pulp and polyethylene (PPE) liner. Continuous thread caps have a single thread on the inside of the skirt. These typically require a full turn before the closure is properly applied. This closure fits a container with a 70-400 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.