This is for one (1) quality marine grade stainless steel (AISI 316) anchor swivel with eye and eye. Each swivel is stamped 316 and 13 showing both the grade of 316 and the size 13mm. The swivels are marked in the metric specification style of 13mm. The Imperial equivalent is generally considered to be 1/2". Not to be used for overhead lifting. AISI 316 stainless is a premium grade of stainless and is considered by many to be best in class. 316 stainless is corrosion resistant and very durable even in the harshest of conditions.