We've got some big news for Casio lovers (all three of you). The company has just debuted its new Pro Trek WSD-F21HR (£399) smartwatch, which has the dubious honor of being the first Casio to feature a heart rate monitor. Given the feature is bread-and-butter stuff in the world of smart wristwear, it's hard to believe this is the first time it's been included on a Casio - but hey, at least it's finally here. Aside from being able to keep tabs on your heart rate via a dedicated watch face crammed with stats, the WSD-F21HR also features detailed colour maps (even offline), a 1.32in dual layer colour LCD and monochrome LCD display, and a lightweight, waterproof design that's built with endurance in mind. Just slap it on, and get trekking!