well , its be 6 month since I purchase the product and the gp function have croak . everything else work but the distance always read zero and do not change . I have try to reset the watch -lrb- hold the mode\/reset + power button -rrb- but that have not help . the watch be not exactly cheap and what be worse be that I never drop it and always wear a wristband under the watch so that it would not get all sweaty so I take very good care of it . I be very disappoint in the product 's lifespan and Amazon only have a 30 day return policy so it look like I be outta luck !