This is for four (4) quality marine grade stainless steel (AISI 316) quick links. Each quick link is stamped 316. 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 for a long service life. This is for four (4) quality marine grade stainless steel (AISI 316) quick links. Each quick link is stamped 316. 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 for a long service life.