This is the number 69 FLAT TOP Standard Folding rear sight. The sight height is adjustable from .360 inches to .460 inches by loosening the screw on the face of the sight and moving the notch piece up or down. The replaceable notch piece (part st52) has a hand painted white enamel diamond and is reversible so you have the option of using the U-shape notch or the V-shaped notch to look through. With a simple brass or nylon punch, this sight drifts into the 3/8 inch dovetail cut in the barrel. This style sight is a great option to use with a tang sight (peep sight) or scope because it folds down onto the barrel. This Rear folding Sight is manufactured by Marble Arms Co. here in the US. They are the same company that made Sights for Winchester, Marlin, Savage, Stevens, Remington, Colt, rifles in 1900. Measuring height on this sight is from the bottom of the dovetail to the bottom of the V or U notch.
