Some great images here from Dave (2015 V50 Fell Running Champ, no less). Have a click through to his site.
Last Updated on 30 January 2016 by the5krunner

tfk is the founder and author of the5krunner, an independent endurance sports technology publication. With 20 years of hands-on testing of GPS watches and wearables, and competing in triathlons at an international age-group level, tfk provides in-depth expert analysis of fitness technology for serious athletes and endurance sport competitors.