The 515CT is a compact 20mm micro optic packed with innovations. Featuring Holosun's Multi-reticle system" the 515CT allows the operator to switch from a 2 MOA dot to a 65 MOA circle dot with a push of a button. Holosun's highly efficient light emitting diodes and Solar Fail-safe technology allow the 515CT optics to run without a battery in many lighting conditions. Additionally" the CR2032 battery lasts up to 5-years. The 515CT is housed in CNC machined Titanium and comes with removable" non-obstructing" clear flip-up lens covers and kill flash. Holosun's Shake Awake technology puts the optic to sleep with no motion and wakes it up" recalling the last setting with the slightest movement" conserving battery life even further. The HE515CT is built for all your needs no matter the weapon platform" environment" or type of use.