It has a knob on the left with 10 ON settings. Each click alternates between off and the next level of on. Once you have a setting you like, one click either direction will be off.
Edit: if in a completely black room with it on 1 or 2, you have to move your head around to the edges of the eyebox to find any red glow other than there dot. Under anything approaching a hunting situation you wont see any red.
Last edited by prm; 12/26/18.
