Please check the manufacturer's website for authorized shops other than [Sold and shipped by Amazon.co.jp] Main uses: Running, swim training, golf, paddle sports (stand-up boards and boats), etc. Key features: Elevate optical heart rate monitor, advanced running dynamics and more Actual dimensions: 42.0 x 42.0 x 14.5 mm Display size: 1.1 inch (27.94 mm) Resolution, width x height: 218 x 218 pixels / transflective MIP color display Weight: 67.0 g (including band) Operating time: up to 9 days (depending on usage mode) Water resistance: 100m Built-in memory: 64 MB (free space 37 MB)