a laser beam generating module capable of projecting a series of concentric circles of light is connected to the frame of a firearm in substantial alignment with the gun barrel . the laser beam can be actuated on demand , and the resultant pattern will be projected onto the target . due to the intrinsic fan angle of the spatially projected beams , the circles displayed on the target will appear to be spaced further apart when the target is further away , and appear to be spaced closer when the target is nearer . by selecting a suitable laser fan angle , it is possible to get an immediate visual indication of the approximate range to the target increasing the potential accuracy .