DG19-50A Model Glass Road Studs. DG19-30C Model Glass Road Studs. 1.Drill a hole, the diameter of 100mm, depth of 24mm, and clean it. 2.After the adhesive dries, pour in right amount of epoxy resin or asphalt glue. 3.Put glass road studs into the hole, then spin it slightly to push out epoxy resin or asphalt glue. Next： Solar Road Stud.