The Diode Module inserts into the chamber for adjustment of sights at 25 yards in order to get the firearm "on paper" to save both time and ammunition when sighting in. The Diode Module includes CR123 "button-type" battery cells and a foam lined storage case. Purchase Sight Arbors separately by caliber.
Battery Type and Number: CR123 "Button-type" Cells
Batteries Included: Yes