This Remington manufactured late variation rear sight assembly includes the aperture, slide, elevation screw, windage screw, and (hollow) base. This rear sight assembly is for the model 522 Viper semi-auto rimfire rifle and is in excellent condition with light wear. The base mounting screws are sold separately.  (file photo)

Note: Firearms with the following serial numbers have been observed with this part: 3099981, 3106813, 3112852, 3121044, 3190437, 3209072, 3227645, 3232240, 3232451 & 3247065.