This is for ten (10) quality marine grade stainless steel (AISI 316) pad eyes. The pad eyes are in the US specification of 1/4", the metric equivalent is generally considered to be 6mm. The overall length is 2 3/8". The center of eye to center of eye measurement is 1 11/16" 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.