This is a quality marine grade stainless steel (AISI 316) chain ideal for marine applications or where corrosion resistance is required. Great for light applications that require corrosion resistance. The link size is 5/32" or 4mm in the metric equivalent. There is 50' of chain in a poly bag. 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.