Sawtooth Outdoor Products Peep It 3/16 in w/Peep Aligner, Pink, 3/16, 759740007335

So when you draw the bow the elastic tube will stretch and align the aperture to a perfect perpendicular stance so you can see through the aperture. This Serve-less Peep It also installs in seconds and doesnt move yet can be micro adjusted without a bow press.