For the target shooter, there is a 1/4" hole size with approximately 3/16" view. The clarifier will make the target crystal clear allowing you to pick out the details at a distance. The larger opening allows more light transmission than our standard 1/8” clarifiers for better low light shooting. This clarifier is also designed for hunters using a lens in their pin sight. The clarifier will work in the Super Peep 1/4" Housings (749-37L or 749-37LH).