This is a Holosun Technologies Red Dot known as the 403C, model HS403C.
The HS403C is a solar version of the successful HS403A. Holosun's highly efficient light emitting diodes and solar panels allow Holosun solar optics to run without a battery in many lighting conditions. Additionally" the back-up battery lasts up to 5-years. The HS403C is compatible with standard mounts.
Features:
Designed for day and night use
2 MOA on dot size
Parallax-free
Unaffected by extreme weather conditions
Durable construction
