This is for two (2) quality 316 marine grade stainless steel quick links at 5/16" each. The metric equivalent is 8mm. Dimensions are displayed on the image page (8mm thick, 90mm long, 33.5mm wide, the quick link can be opened to 10mm). Not to be used for overhead lifting. 316 stainless is corrosion resistant and very durable even in the harshest of conditions. Working Load limit is 1,525 Lbs. The quick link is perfect for a variety of applications. It can be used indoors, outdoors, sporting, boating, rigging, as a chain connector, with rope, camping, shade sails, swing cable connections. Ideal for securing rings and loops to chain or for extending chains. The quick link threaded nut can easily be twisted clockwise to open and anti-clockwise to close.