This is for four (4) quality marine grade stainless steel (AISI 316) 1/4" UNC lifting eye nut. Each bolt is stamped 316 and 1/4" (for the size). The bolts are manufactured in the US style of 1/4" UNC. 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.