This is for one (1) quality marine grade stainless steel (AISI 316) bow shackle. Each shackle is stamped 316 and laser etched 1/4" with the manufacturer's mark. The shackles are marked in the US specification style of 1/4" (for the shackle size). The Metric equivalent is generally considered to be 6mm. This is a forged shackle, which for load bearing applications is better than a cast shackle. 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. Working Load Limit 935 lbs. Black Nitride products undergo thermal chemical diffusion and quench bath treatments for unmatched durability and performance. With a case depth of 0.001", they offer increased wear resistance, improved fatigue strength, enhanced lubricity, and corrosion production. Black Nitride products are ideal for demanding applications while maintaining a sleek matte, professional look.