Name:stainless steel back bolt marked by ourself factory Size:DN15-DN100, 1"-6" Standard:DIN, SMS, 3A,ISO High quality Name:stainless steel back bolt marked by ourself factory Size:DN15-DN100, 1"-6" Standard:DIN, SMS, 3A,ISOHigh quality,and competitive price .Manykinds of size accordings.If you have some interesting , welcome contact with us by details .