This is the Directed 8504D DIGITAK add-on sensor. Three sensors in one module: shock, tilt and temperature.

Shock detection, two stages

A light knock gives a warning chirp, a real strike sets off the full alarm. That distinction is what stops your alarm firing every time someone brushes past in a car park.

Tilt detection

This is the part worth paying for. A shock sensor detects impacts. It does not detect a car being quietly jacked up in a driveway, and that's how wheels and catalytic converters disappear. Tilt sensitivity is adjustable, so you can set it to ignore a sloped driveway while still catching a jack.

Temperature, and automatic remote start

The sensor also reads cabin temperature, which lets the system start the vehicle automatically when it gets too hot or too cold rather than on a fixed timer. On a Canadian winter morning that means the car warms itself when it actually needs to.

D2D connection

It connects over Directed's D2D (digital two-way) bus rather than analogue wiring, so it's a plug-in rather than a splice, and the system reads it as a proper digital sensor.

Requires a compatible Directed or Viper system, sold separately.

Looking for shock detection only? The 504D Stinger DoubleGuard is the simpler and cheaper option, though it has no tilt or temperature sensing.

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