This is for ten (10) quality marine grade stainless steel (AISI 316) Round Ring Welded 4mm x 20mm (5/32" x 3/4"). 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.