Electro-luminescent backlight.
Altimeter:Range: -500 / +9000 m, rsp. -1600 .. +29500 feet .
Resolution : 1 m, rsp. 3 feet.
Minimum and maximum altitude.
Barometer: Range: 300 - 1100 mBar, rsp. 8.90 - 32.40 inHg.
Resolution: 1 mBar, rsp. 0.05 inHg.
Temperature:: Temperature range: -20 - +60°C, rsp. -5 - +140°F.
Resolution 1°C, rsp. 1°F
Heart rate monitor: Display range 30 - 240 beats / min.
Adjustable heart rate limits.
For post-performance assessment, Suunto X3HR stores data on training duration; average, minimum and maximum heart rate; cumulative ascent and descent; and the highest and lowest altitude in the training session. It can also store up to 10 split/lap times with the heart rate in each training file. The memory can hold data for up to 10 training sessions.
New Suunto transmitter belt are included with SUUNTO X3hr.
1/100-second stopwatch.
Measuring capacity: 19:59'59,99''.
Alarms.
Resin case and band.
Dimensions: FOR MEN.
Wide: 50 mm.
Length: 40 mm.
Height: 15 mm.
Weight: 46 g.
Warranty: 2 years.
You can see Instruction manual (PDF) here