Hi Evan, like I tell everyone - you would always prefer to scare people away BEFORE they get in and this device works perfectly. Really happy with it. Friends of mine have purchased them too and are happy.
The one I have is made by ‘Home Safe’ Model 639SR (it is an older model now I guess so you may not find this exact model). From memory I paid about $90 Australian but saw them after I purchased it for a bit less - typical when I buy something. It features:
Visitor Chime and Watch Dog/Alarm with Remote Control.
Sensor detect motion activates Bark or Chime or Alarm (siren).
Adjustable detect sensitivity, detect range 0-7 Metres
Detect angle 150 Degrees
Sound adjustable volume, sound power to to 5W
10 Seconds voice recorder (optional) - never used this.
Bark/Chime/Alarm sound select switch
Wireless remote control for ARM/DISARM/PANIC
AC adaptor operation (included) with AA Size batteries x 8 backup (not included)
Compatible with additional total 16 wireless unit to expand the system - I have it programmed to use 2 units working off of one wireless remote but you can have it programmed to have a remote dedicated to each unit if you prefer.
The main unit built-in microwave detect sensor can penetrate through wood, plastic, cement, etc. but cannot penetrate Metal Objects, Objects containing metals or other electric objects and ultra-thick barriers, etc. I have a glass panel at my front door and it works through glass no problem.
Other compatible optional wireless accessories include:
Model 616PR Wireless outdoor motion detector sensor
Model 615PR Wireless motion detector sensor - I guess this is the indoor version
Model 623T9 Wireless doorbell push button - probably for the Chime
Model 218WR Wireless slim door/window sensor
Model 600WR Wireless door/window sensor with alarm
Hope this helps - can’t recommend highly enough if you can get one.