Rugged and Reliable: The Vortex Defender-ST 6 MOA Micro Red Dot is ready when and wherever you are. Rugged and reliable, it has an absolutely large sight window Large Hard Coated Aspherical Lens: The DFST-MRD6 features large hard coated aspherical lens for distortion-free sight picture and truer colors Enhanced Battery Life: The motion activation feature of this red dot sight has a 10 minute auto-shutoff that automatically activates with motion while 10 minute auto-shutoff saves battery life Shockshield Polymer Insert: To protect against hard, daily abuse, the micro red dot features a shockshield polymer insert Ideal Fit: The Vortex Defender-ST 6 is designed for recreational shooters, law enforcement, and aspirational hunters