This is for one (1) quality marine grade stainless steel (AISI 316) M10 turnbuckle rigging screw with jaw and swage (the swage suits 1/4" or 6mm wire). Each turnbuckle is laser etched with the grade of 316 and the size of M10. The imperial equivalent is generally considered to be 3/8". Each turnbuckle comes with a locking nut on each end. 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.