The wireless occupancy sensors (WSCxx-IRW) have built-in solar cells that draw on available ambient light to power themselves and can operate for up to 48 hr in total darkness. Batteries are not required for continuous operation, however batteries can be added as an option for applications without available ambient light. For improved detection, the sensors use an enhanced PIR element located directly behind a unique multi-zone optical lens. This exclusive fresnel lens establishes twice as many zones of detection as traditional sensors. The zones can be configured (masked) to block out unwanted traffic zones (i.e. Outside hallway traffic). The WSC15-IRW features superior detection for parallel and perpendicular motion. Innovative sensing technology detects motion moving directly towards the sensor. The self-powered wireless sensor design also overcomes the placement and coverage challenges of traditional sensors. Self-powered wireless sensors enable flexible placement allowing sensors to be mounted wherever needed without the complexity of moving or installing new wiring.