The B051NSL is a 1 gallon natural-colored HDPE plastic f-style container with 38-400 neck finish. An f-style container is typically a larger container with a handle. These containers are typically used for industrial, economy-sized products like cleaners, chemicals, automotive fluids, bleach, and more. High density polyethylene (HDPE) is marked with the resin identification code of 2. HDPE has a high tensile strength, good resistance to chemicals, good impact resistance, highly rigid, and highly scratch resistant. This item has a 38-400 neck finish. The first number refers to the diameter (in mm), and the second refers to the closure depth, style and thread. This container can be paired with a closure with a matching finish. natural-colored containers are not actually colored. This is the natural color of the plastic, which is a milky translucent color. This translucent color shows product level, or how full (or, if you're a pessimist, how empty) the container is.