Burris Speed Bead Beretta 390 Mallard 12ga. The radical SpeedBead System handles many of the factors that make wingshooters miss, and turns poor shooters into good shooters and good shooters into great ones. With the SpeedBead System, both the target and the red dot remain in focus. The optics and their position on the sight plane eliminate the need for perfect left/right, up/down head position for an accurate shot. The innovative mount puts the center of the optic directly in line with the ventilated rib, so altering your shooting style is not necessary. And with 3-1/2 inches to 4-1/2 inches of eye relief, there is absolutely no worry about your eyebrow running into the sight nor any interference with your hand gripping the shotgun. Should the common CR-2032 five year battery ever fail, you can revert to your front bead without visual obstruction. For a better view on rising targets, there are 1/8 and 1/4 risers available.