Our Product

Frontline Defense Systems Inc. is the world’s only manufacturer of the patented Full-Length Interlocking Astragal Door Lock, known as the Interlocker for short.

The Interlocker is the simplest, most basic method available to secure your property from forced access.

Designed for both out-swing and in-swing doors, Frontline’s latch protectors are offered in both aluminum and steel, available in several standard colours, and can be customized to fit any size of door.

Installing the Interlocker is easy.

All you need is the following:

  • Drill
  • 3/16” metal drill bit
  • 9/32” metal drill bit
  • Step bit
  • Heavy duty rivet tool
  • Size 3/16” Allen wrench
  • Hammer
  • Combination square
  • Level
Installation Instructions for INSWING
Installation Instructions for OUTSWING

How It Works

Criminals typically gain forced access to properties with a pry bar or similar device to pop doors open. Frontline’s Interlocker makes this nearly impossible by protecting the full length of the door.

With the vast majority of property break-ins being crimes of opportunity, Frontline’s door latch protectors will deter most would-be burglars and other intruders.

Where To Find Our Product

See here for our list of distributors or contact your local locksmith and ask about Frontline Defense’s full door latch protectors.