The Verifier has a lens in it similar to the ones in your reading glasses that will allow you to see your sight pins better on your hunting sight. Don't let changes in your vision compromise your ability to make the shot. The verifier lens sharpens the picture so pins are easy to see. The 1/4" aperture (viewing area 3/16") is available in your choice of #4 (silver mark), #5 (purple mark), #6 (pink mark), #7 (blue mark), #8 (white mark), or #9 (orange mark) verifier. This verifier fits in the 749-37L or 749-37LH Peep. - See more at: http://www.specialtyarch.com/products-page/verifiers/verifier/14-verifier/#sthash.6F0grMcN.dpuf