The Pro Series Peep is a sculpted to trim weight and boost bow performance. – Hooded peep helps reduce glare on Clarifier and Verifier lenses. – Peep opening is 3/16″ with no Apertures, Clarifiers or Verifiers installed. Accepts all Specialty Archery 1/8″ and smaller Apertures, Clarifiers & Verifiers. We recommend use of the Dual Aperture Wrench (#210078) for insertion of optional Apertures, Clarifiers & Verifiers. To protect your peep from dust, debris and moisture we recommend the Peep Guard.