This is for one (1) quality marine grade stainless steel (AISI 316) square quick link 3/8". The metric equivalent is generally considered to be 10mm. Each quick link is marked 316. 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. Breaking Load = 13750lbs