Aperture Kit with the three largest apertures 1/16, 3/32, and 1/8. The three apertures will interchange in all Specialty Archery Peeps without removing the peep from the string. You will need a reducer (753-3) if you want the apertures to fit the 749-42LH or 753-1 peeps. Kit includes 3 apertures (1/16, 3/32, 1/8), clear storage case, and dual aperture wrench.