Product Testing: STI-6400 Exit Stopper

May 2, 2018
This multifunction alarm helps prevent unauthorized exits/entries with signage and a piercing horn when triggered

A statement from Safety Technology (STI) precisely explains their product line. "STI is a global manufacturer of protective enclosures/cages and push buttons. Our products help prevent false alarms, deter theft and minimize vandalism of fire alarm devices, communication routers and other equipment..."

The first STI product was a protector for fire alarm pull stations. STI now offers more than 1000 products covering six categories: fire and safety, enclosures and covers, buttons and switches, wire cage protectors, vandalism and theft and products for home and business.

An STI-6400 Exit Stopper has been chosen for review. This economical product is designed to prevent unauthorized exits and entries through emergency doors. A perfect application is to monitor remote exit doors in retail businesses, but many other applications may be found such as in nursing homes and day care centers.

Descriptive signage on the STI-6400 describes its purpose. A bright red cover plate contains large “STOP” wording to alert anyone approaching the exit door. Additional "Emergency exit only" plus "alarm sounds when door is opened" wording explains the purpose of the product and what the outcome will be if someone tries to open the door. If after all of these warnings a person does open the door, a piercing 95 decibel horn will sound.

The basic STI-6400 unit is self-contained and is operated by a single 9-volt battery. A magnetic contact is used to maintain the STI-6400 in a silent mode. When the door is opened, the magnetic bond is lost which activates an electronic circuit and sounds the alarm.

Mounting of the STI-6400 is dictated by jobsite door and frame configurations. The magnetic contact located inside the unit is mounted on two posts. Additional posts are located in four quadrants within the unit. This allows the magnetic contact to be relocated to left, right, top and bottom positions in the STI-6400 unit depending on the application. A standard installation would be to install the magnet holder on the door frame and the 6400 unit on the door.

Depending on door/frame configurations, the STI-6400 can also be mounted on the door frame and the magnet holder installed on the door. The magnetic contact inside the unit is connected to an extra-length wire harness. This makes it possible to mount the magnetic contacts and magnet holder units together in a separate location with the wire harness connecting back to the separately-mounted STI-6400 unit.

Switch buttons located within the unit allow several different alarm options. Settings include horn volume, either 105 dB or 95 dB, horn duration, either 30 seconds, 180 seconds or continuous, horn sound (trip), either immediate or 15 second delay, arming, either immediate or 15 second delay. A terminal blank inside the unit options provides connections for external power, reed switch terminals and key switch connections.

STI-6400 is designed for single door applications. STI-6402 is a single unit with two sets of magnetic switches. This allows on unit to control a double-door opening. STI-6403 provides for remote horn remote horn installations. STI-6404 provides both double-door and remote horn usage. STI-6405 has a momentary reset function. The unit is always 'on' keeping the exit door protected at all times. STI6400WIR units are also available. Wireless signals can be sent to an 8-channel receiver which can identify the door being opened.


Installation of an STI-6400 nit is short and simple. Begin by determining the best location so the STI-6400 and magnet contact can be installed in close proximity on the door and frame. Our installation required the unit to be mounted on the door and the magnet holder to be mounted on the door frame. The magnetic switch was relocated to the top position inside the unit. Four screws are included to mount the STI-6400 to the door. Two screws were used to mount the magnet holder. We mounted the magnet holder first, and then used double-backed tape to temporarily mount the STI-6400 in position and for trial operation before finally drilling holes for the unit mounting screws.

The red cover plate easily snaps into positon. A final step is to install a furnished security screw which deters tampering. A special tool is included for tamperproof screw installation. All units are recommended for indoor use. STI recommends that you change the 9 volt battery twice a year.

The STI-6400 is only one of the 1000+ safety and security products made by Safety Technology. For more information contact your local locksmith distributor or: Safety Technology International, 800-888-4784,