The quality of the heat preservation nail coupon level and use
insulation screw bolt is also called mosquito-repellent incense bolt, its material is galvanized sheet or lulu patches. According to the grades of quality distinguish several levels: level 1. A grade of bolt is made of high quality galvanized sheet stamping forming, is composed of automation machinery automatic stamping, such coupon is no waste, such as a quality a. Bottom 3 cm diameter, four holes on each side, the inside of the hole out of the two grooves, for glue adhesion strong, small cock of the tongue, at the centre of the workers as long as holding small tongue, dip in on glue, paste on the wall, easy construction.