Meprolight M21-X Self-Powered Day Night Reflex Sght XreticleMeprolight M21-X Self-Powered Day Night Reflex Sght XReticleFeatures of Meprolight M21-X Self-Powered Day Night Reflex Sght Xreticle Dual illuminated 1X “Red-Dot” reflex sight. The MEPRO M21 provides instant, all-light aiming without batteries. Maintenance FREE! No batteries, No switches a..