This is a BSA Optics Red Dot known as the HMRGBD30CP, model HMRGBD30CP.
The sight features a red" green and blue 5 MOA dot that is adjustable via the 11-position rheostat and powered by a 3V CR2032 battery. The integral mount will fit both 3/8" and 5/8" Weaver-style rails.
Features:
MAGNIFICATION LOW: 1X
MAGNIFICATION HIGH: N/A
OBJECTIVE LENS DIA. (MM): 30
ADJUSTMENT GRADUATION (MOA):1/2
LENS COATING: Multicoated
W/E ADJUSTMENT RANGE: 45
EYE RELIEF (INCHES): Unlimited
FOV LOW @ 100' (FT): 68
FOV HIGH @ 100' (FT): N/A
PARALLAX SETTING (YDS): 50