What's The Difference Between The Vista 15P and 20P

https://www.geoarm.com/vista-15p-honeywell-alarm-control-panel.html

https://www.geoarm.com/vista-20p-honeywell-alarm-control-panel.html

The Main difference between the Vista 15p & 20p is the onboard zones size:

The Vista 15P has 6 onboard zones while the Vista 20p has 8 on board zones

The Vista 15P is also not a partitionable system.

Installation Manual For More Information:

https://turbifycdn.com/ty/cdn/yhst-51756635596032/honeywell-vista-15p-control-panel-installation-setup-guide.pdf