The T.A.S. features a light tunnel were the bright aiming dot becomes visible once the shooter has a good sight picture. Then use the sight just like you would an electronic red dot.
The single dot sight provides extremely rapid and intuitive target acquisition. Shooting with both eyes open the T.A.S. aiming point seems to float in space. Put that dot on target to hit the target.

This item includes:

• TAS Glock sights are available in Green or Red options.
• User Guide