The OEM Ergodyne Skullerz Elastic Retainer Strap EGO59991 is designed for easy use, featuring a simple twist-and-lock mechanism for immediate application. Made from elastic material, it provides a snug and secure fit to prevent movement during use. This dynamic design allows compatibility with a foam gasket insert (sold separately) and is suitable for use with Odin, Dagr, Kvasir, and Valkyrie safety glasses.