Up to:
12 floors in building
250,000 sq. ft. in a warehouse or retail store
3,000 acres on a farm or ranch
Features:

Multiple handsets (up to 36 per base unit)
Multiple lines (4-ports / lines per base unit)
Works behind any analog port of a PBX, phone system or analog phone line
Durable
Reliable
Ease to use
6 hours talk time, 50 hours stand-by time
Optional external antenna for indoor use in warehouses and manufacturing plant or outdoor use on farms and car lots