This is for one (1) quality stainless steel (AISI 304) D shackle. Each shackle is stamped 304 and the makers mark. The shackles are marked in the imperial specification style of 5/16" (for the shackle size). The metric equivalent is generally considered to be 8mm. This is a forged shackle, which for heavy duty applications is better than a cast shackle. Not to be used for overhead lifting. AISI 304 stainless is a standard grade of stainless.