it's the red dot sight of EK Archery that equips all Cobra R9 Deluxe crossbows
This is the viewfinder that comes in the Cobra R9 Crossbow Deluxe Kit
It is mounted on rails 21mm wide.
This viewfinder requires a CR2032 battery (included) and adjustment is very easy thanks to two knobs on the back and side of the viewfinder.
Length: 11.5 cm
Width: 4.6 cm
Height: 5.5 cm
Weight: 58 grams