Despite the black background, the display is legible in daylight and light provides excellent night vision. Too bad the lighting is as short and not adjustable.
Illuminator This function turns off after 6 hours to save battery life, it is not adjustable either.
Visual indicators for alarm and other features are very small and hard to spot, the alarm tone is a bit feeble but sufficient.
Integral thermometer gives the temperature greatly increased because of the body temperature, count 10 degrees too less.
The large mesh size of the bracelet makes it difficult to control the wrist but a setting on the clasp can compensate.
Without the benefit of reliability and accuracy in the long term, I am delighted with my purchase.