The 552 advanced dot sight from Strike Systems is well constructed in metal and hard plastic.
It features a rear-facing keypad, with on/off and controls for changing the color of the reticle, red or green, as well as adjusting the brightness of the reticle. Fully adjustable windage and elevation.
The two AA batteries are stored in an easily accessible compartment that is securely lock by a lever, allowing fast and easy change of batteries should it be necessary.
The sight has an simple screw on locking system that enables you to mount it on any standard picatinny/weaver rails.