Installation begins with one 3/8-inch frame bore. After the body is pressed into place, the screw is adjusted to meet the closing surface without being driven beyond its travel. The published movement is 0.25 inch overall, with 0.11 inch of pre-travel and a plus-or-minus 0.04-inch tolerance. At the terminals, the Form A reed provides a normally open, closed-loop circuit rated for 10 W, 200 VDC, and 0.5 A.

This is a mechanical interface as much as an alarm component, so adjustment matters more than appearance alone. The opening should be metered through repeated cycles before the adjustment is considered final.

GRI specifies 0.25 inch of total travel and 0.11 inch of pre-travel, plus or minus 0.04 inch. The terminal model uses a normally open Form A reed on a closed loop and carries a 10 W, 200 VDC, 0.5 A rating. Press-fit construction keeps the visible footprint small, and the adjustment screw can be removed for gaps of 3/16 inch or less when the installation calls for it.

In a carefully planned home security system, this switch can protect a difficult opening without adding a separate surface magnet. The plunger must be adjusted before the window or door is fully closed; Allied verifies clearance and repeated operation so the frame does not damage the switch.

The short body sits behind a screw-down flange, while the ball accepts pressure from any direction as the opening closes. Its published movement is 0.2 inch overall; operation begins after 0.08 inch of pre-travel with a plus-or-minus 0.03-inch tolerance. Electrical connection is made at the terminal block, where the normally open Form A reed serves a closed loop rated at 10 W, 200 VDC, and 0.5 A.

Every frame still has to be treated individually. The ball should restore the circuit without bottoming out, and GRI excludes bottom and side tracks because debris and lateral force can compromise movement. Allied checks the mounting depth, meters the loop, and cycles each door before the group is commissioned.

GRI specifies 0.2 inch of total travel with 0.08 inch of pre-travel, plus or minus 0.03 inch. The white terminal-block model uses a normally open Form A reed on a closed loop and carries a 10 W, 200 VDC, 0.5 A rating. A screw-down flange, mounting hardware, and spacers help establish a firm, repeatable position in the frame.

This can be a practical replacement when an existing hardwired alarm system already uses roller-actuated door contacts. Allied confirms the switch is not placed in a bottom or side track, sets the depth so the ball moves freely, and cycles the opening to verify dependable restoration.

Each 100-T-B can be secured through its flange or with 3M adhesive, and the terminal version keeps the field wiring accessible behind the included cover. GRI publishes a standard gap of up to 1 inch for the 100-T family. The normally open Form A reed is closed-loop rated at 10 W, 160 VDC, and 0.4 A, with a hermetically sealed assembly and plated contacts for long service life.

For a tidy home security installation, the brown finish can reduce visual contrast on stained or bronze-colored frames while still leaving the contact serviceable. The mounting surface, magnet alignment, terminal cover, and zone response should all be checked before the opening returns to daily use.

Steel changes a magnetic contact’s operating distance, so GRI publishes a 1/2-inch standard gap on steel for this model. The contact includes 12-inch 22 AWG leads and uses a normally open Form A reed on a closed loop, with a 10 W, 200 VDC, 0.4 A rating. The white 180-12-W is also identified in the manufacturer family as UL 10C fire rated.

On a fire-rated or high-use opening within a commercial security system, component selection is only part of the job. Allied confirms the door and frame requirements, keeps the contact aligned within the published steel gap, and tests the zone without compromising the opening’s hardware or function.

The white switch presses into a 3/8-inch opening and provides screw terminals instead of fixed wire leads. GRI rates this exact standard-gap version for up to 1/2 inch, 10 W, 200 VDC, and 0.5 A. The normally open Form A reed operates on a closed loop, and the hermetically sealed, plated contacts are designed to resist sticking or freezing over time.

Allied tests the contact at the final alignment rather than relying on the catalog gap alone.