Window screw, frame screw (turbo screw) with countersunk head TX30 - for quick, precise, and secure installation of wooden, metal, and plastic windows without the use of dowels. Easy to use: pre-drill the window frame and masonry at once with a small diameter of 6 mm; for lightweight materials and wood, drilling is not necessary at all; there is no deformation of the window frame; installation is without spacers; the advantage is fire resistance.