This is for one (1) quality marine grade stainless steel (AISI 316) Shackle Key sailor tool. Each key is stamped 316. This key is ideal where a quick tool is needed for more secure tightening of a shackle pin. The tool can also be used as a flathead screw driver. This handy tool is ideal for key rings and doubles as a bottle opener. 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.