The ERA-PIR-SPK monitors an entrance and sounds a tone from its built-in speaker when triggered. Mount it above a doorway with the included bracket. Unlike its sister product, the ERA-PRDCR, it does not transmit to a remote receiver; it sounds where it is mounted. It is part of the ERA series.
Most PIR sensors mount on a pivot ball and cannot aim the beam down toward the floor. This bracket lets you rotate the lens up and down to aim the beam straight down at a doorway, so it does not bleed into other areas. In a convenience store, for example, that detects people coming through the door without catching general foot traffic inside the store. Suited to areas up to 3,000 ft, the tone has volume control and is meant to notify rather than alarm; for a louder alert, see the ERA-PRDCR.