The Advanced Combat Optical Gunsights (ACOGs) are internally adjustable, compact telescopic sights with tritium and fiber optic dual-illuminated reticle patterns for use in low light or at night. Bindon Aiming Concept (BAC) models feature bright daytime reticles using fiber optics, which collect ambient light. The ACOGs combine traditional, precise distance marksmanship with close-in aiming speed.