The product is a set of two 1/2-13 left-hand thread steel nuts, designed for external hex drive style applications. These nuts are made of steel with grade 5, and have a reverse thread design. The nuts come in a pack of two and are ideal for use in various industrial and fastening applications where a left-hand thread design is required. It is important to note the California Prop 65 warning associated with the product, indicating potential health and safety concerns.