Heat Index Stopwatch: Accurately Calculates Temperature, Humidity, Heat Index and Dew Point * Features 30 Dual Split Recallable Memory/ Measures Up To 10 Hours With 1/100 Second Resolution * Includes: Pre-Settable Countdown Timer With Auto Repeat Function/ LED Backlight/ Time, Calendar and Alarm Display * Solar Powered With Back-Up Lithium Battery * Water Resistant