SSP Eyewear Red Eye Dominance Correction Kit comprises of a full set of Redeye blister packed. You can use any of the four sizes of Redeye but it is recommended that you start with the 16mm diameter and with practice you should be able to reduce the size of the Redeye being used. Occluding one eye by closing it or blocking it completely, loses depth perception, judgement of speed, field of vision and peripheral vision, Redeye gives you the opportunity to reduce any loss of vision to the bare minimum. FeaturesFully adjustableEasy to fit and removeWill not move during shootingCan be used with most precision glassesSmallest currently availableWill not damage glasses