There are several helmet mounts. It all depends if you have a vented helmet or not.
If it's vented, you can use the Contour 2755 Flex Strap Mount or the VholdR Vented Helmet Mount Support system. went with the Flex Strap since you can use it for other mounting options as well.
If it's a vented helmet, you can get either the Contour Flat Surface Mount or the Contour Rotating Flat Surface Mount.