Installation Instructions: osition Jamb plate (the piece with the moving arm) on the door jamb located on the door frame and mark the screw hole locations with a pen or pencil. n your marked holes drill 3/32 inch pilot holes to get a more secure grip and prevent splitting your door frames and breaking off your screws. ith a 1-1/4 in. (3.2 cm) gap, position catch arm on door opposite of jamb plate and in the same way mark and drill 3/32 inch pilot holes. ow that you have the pilot holes to guide you, simply install and tighten the Heavy Duty Door Security Guard with the provided screws. Technical Details: Zinc die cast material and bright brass plating used in this product offer exceptional corrosion resistance. Zinc die cast alloy provides the best combination of strength, toughness, rigidity, bearing performance, which makes this door latch lock far more durable than other flip locks. Zinc's mechanical qualities compete with and often exceed those of cast aluminum, magnesium, bronze, plastics and most cast irons. These characteristics, coupled with the superior bright brass finish make this home security door lock an unrivaled choice.