Seiko 5 Sports Men's Automatic Watch with Green Nylon Strap SRPD77K1. The Seiko 5 Sports range boast Seiko’s new upgraded 4R36 automatic. It is the same movement that is found in more expensive Seiko models, such as the ‘Turtle’ that belongs to the Prospex range. The movement consists of 24 jewels and it operates at 21,600 beats per hour, this ensures the watch has 40 hours of power reserve. It includes Seiko Diashock, which essentially protects the inner mechanisms from any damage the watch may sustain if it were to be dropped or knocked. It is expected to either gain or loose between +45 / -35 seconds per day. Finally, this watch has a water resistance of 100 metres, making it suitable for swimming and snorkelling.