This is a Hi-Viz Sight known as the Spark III, model SK2011.
HIVIZ(R) Spark III Shotgun Sight. Screw-Attach design replaces the front bead on a shotgun. Includes Green" Red and White replaceable LitePipes.
Features:
Bead replacement front sight
Fits most vent ribbed and plain barrel shotguns w/removable front bead
Green red and white LitePipes;Round shape .090 diameter
