In connection with my heart rate monitor PM80 the Speedbox 2 works without any problems and accurately. The commissioning was completed within minutes. The precision is sufficient even without calibration run for me. Unlike GPS watches do not have to wait for satellite reception. Just start walking - the measurement starts immediately. Irritation and measurement errors caused by intermittent reception time does not exist. The German manual leaves no mystery open and contributes to good overall impression bei.Beurer 676.21 Speedbox II footpod Pulsuhrzubehör