The Go Pro Hero 4 Session is the smallest GoPro ever built. It is 50% smaller and 40% lighter than previous GoPros allowing it to be mounted on places previously impossible. This GoPro has simplified one-button controls, is waterproof out of the box, and is compatible with most GoPro accessories. It comes bundled with its own ball joint buckle for mounting on helmets. The Hero 4 Session retails for $399.99.