This is a Hi-Viz Sight known as the Snap On, model MPB.
HIVIZ(R) MPB Shotgun Sight. Fits all 12" 16 and 20 Gauge plain barrel shotguns without ventilated ribs. Includes two Green and two Red round" replaceable LitePipes.
Features:
Front sight
Fits all 12 16 and 20 gauge plain barrel shotguns;Two green and two red LitePipes;Round shape
