Place the IR light barrier strategically so it can warn you when someone is near! Applications : announce visitors, warn against burglars, set boundaries, science projects,...
Specifications:

1. audible (85dB) and visible (LED) alert
2. range: 1 to 4m (3.3ft to 13ft)
3. on/off switch provided
4. power supply:
   1. transmitter: 9VDC / 50mA max.
   2. receiver: 9VDC / 20mA max.
   3. 9V battery holder and adapter jack included
5. dimensions:
   1. transmitter: 55 x 40mm / 2.2 x 1.6"
   2. receiver: 100 x 50mm / 3.9 x 2.0"
6. not recommended for outdoor use

manual_wsaa120.pdf

receiver.jpg

transmitter.jpg

module_diy_kit_guide.pdf