This is for one (1) marine grade stainless steel (AISI 304) D shackle with a slotted flat pin 3/16". Each shackle is laser etched with 304 and the metric size of 5mm. Each D shackle is stamped with the imperial size generally considered to be 3/16". The shackles are marked in the US size specification. A "Flat Head Screwdriver", technically called a slotted or straight-slot screwdriver, is needed to correctly tighten the pin. Not to be used for overhead lifting. AISI 304 stainless is a standard grade of stainless. Breaking load 2200lbs.