The keyed deadbolt for storm and screen doors complements the appearance of GL Series lever handles while adding additional security to your home. It allows you to keep your main door open and enjoy the light that comes in through a storm door while still feeling secure. It is not a high-security lock, but a secondary level of security. The key allows you to lock your storm door as you leave the home, and unlock it if someone inside has locked the door. Installation is easy and should take about 20 minutes. Only three small 5/16 in. holes are required to be drilled through the door for the screws and spindle. Only a tape measure, drill and screw driver are required. A centre punch to mark the holes is handy, but not required.