Holosun

The HS503R is a 20mm micro optical red dot optic that features Holosun's new rheostat dial to adjust brightness settings, red 2 MOA dot/65 circle size, unlimited eye relief, unlimited field of view and has a IP67 waterproof rating. The HS403R can achieve a constant "on" battery life of up to 100,000 hours. Includes lower 1/3 Co-witness mount, T10 L key, low profile mount, rubber cover, CR2032 battery, lens cloth and user manual.