Products description :It is composed of an O-ring bolt and sleeve , DIN125A washer hex nut and round nut .It is easy to use and easy to operate, and belongs to internal expansion. The round nut is put into the wall, and the hex nut is screwed to rotate the round nut in the wall to achieve the effect of tube wall expansion, so that the product is firmly fixed in the wall. The package is white box + kraft paper box + wooden tray.