red dot sight
Type of non-magnifying optical sight where the aiming point light is projected onto a partially reflective sighting window
en-GB/ˈɹɛd ˈdɒt ˈsaɪt/
en-US/ˈɹɛd ˈdɑt ˈsaɪt/
Type of non-magnifying optical sight where the aiming point light is projected onto a partially reflective sighting window