OnGuard by Hilco OG240S is fully prepared to take on the day with you. They have V-port Technology for enhanced peripheral vision and ventilation. With their removable nose bridge, they can be replaced after a long day of movement and sweat. This pair comes with a removable temple strap so in case they move when you don't want them to, they won't fall far from your face. If you're seeking more, the OG240S also has a removable full dust dam (sold separately). Prescription ready!