The M120 Series Thermometer's bright display has two key attributes:  First, the 50ft (15m) viewing distance allows you to view it from afar.  Second, the wide 130° viewing angle lets you read the display far to each side.

Combine these and a TempEye° M120 Series Thermometer is visible from 84% of the area in a 50x50ft (15x15m) room.  Here's the math . . .

( (π x 50ft x 50ft x 60°/360°) + (25ft x 43.3ft) - (25ft x 11.6ft) ) / (50ft x 50ft)
= 2,101ft / 2,500ft
= 0.8404
= ~84%