With the Economy Plus package, you purchase all the equipment and pay an annual subscription for the alerts service over a minimum contract of 24 months.
This package is designed for when outdoor and indoor coverage at your location is sufficient.
However, please note that indoor coverage depends on a building's configuration (number of floors, construction standard, and wall thickness), and the materials used in its construction.
Consider including the signal booster to ensure you have sufficient indoor coverage. You can always purchase it at a later date after testing your watch at your location.