The last thing you need when aiming for a PB on your run is to be messing with your tracker. Thankfully this sports band is really comfortable and secure, so you can stay in the zone as you keep plodding on. It'll keep your Charge 4 in place, and it's made from a breathable but tough silicone so it won't distract you by sliding around. This one's for larger wrists - the strap can be adjusted between 180 and 220mm. And because it's water resistant, it doesn't matter if it gets a little bit sweaty or wet in the rain. It's going nowhere, unlike you.