A portable brim can be securely attached to and operate with various helmets such as bicycle, skateboarding, snow sport, mountain/rock climbing, equestrian, and paddlesport helmets as well as hard hats used in construction, utility maintenance, material moving, dock loading, and airport baggage handling, to give the wearer shade and protection from the sun. The brim apparatus includes a center section having a size for fitting about a circumference of the sports helmet and a visor outwardly or radially extending from the center section. In one brim apparatus the center section features a stop surface that opposes an upper surface of the visor when the apparatus is affixed to the headgear such that the visor is prohibited from flipping upwards or sliding down or coming off during use.