This threaded, front bead replacement sight is interchangeable and includes red, white, and green fiber optic pipes. Each Spark III is packaged with five threaded studs (6/48, 3/56, 5/40, 3mm x .5, and 3mm x .6) to fit most common shotguns with a removable front bead. The fiber optic pipe is 0.090 inches and the overall height is 0.160 inches. Price is $17.99.
HiViz Spark III Shotgun Sight