This is for one (1) quality marine grade stainless steel (AISI 316) chain connecting link. Each link is stamped 316. The links are made in the imperial specification style of 5/8". The metric equivalent is generally considered to be 16mm. The links are ideal for connecting two pieces of chain. 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.