It's a fine optic for the price - TRYBE Optics 1x24mm Mini Advanced Ruggedized Optic Red Dot Sight, RMR Footprint

I bought this for a back-up/non-magnified sight for an precision AR build with the intention of mounting it on a 45 degree mount. The glass is clear, and it comes with the appropriate mounting options. The rubber cover that it comes with does not fit securely over the optic and will not remain seated on it with any type of movement. The battery loads from the bottom, so replacing it is a bit of a pain.