A red-dot sight with a 2-m.o.a. reticle and a 22 mm objective lens, the Vortex SPARC AR’s Multi-Height Mount system allows it to provide either absolute or lower-one-third cowitness with standard AR-15 iron sights. Rear-facing controls and a front-mounted battery compartment mean the unit doesn’t need to be removed from the gun in order to replace its single AAA battery. The SPARC AR has 10 illumination settings; the lowest two are compatible with night vision equipment. Price: $259. Contact: Vortex Optics; (800) 426-0048; vortexoptics.com.