Item you are bidding on
A complete Redeye kit, which consiste of a hardened black plastic protective case, 5 Redeye discs, there is one 16mm diameter, one 12mm diameter, one 10mm diameter and two 8mm diameter, one 8mm diameter disc is the backing for the other four sizes, the kit comes blister packed and with full instructions.

How Redeye Works
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 may 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.

Some basic facts about Master Eye
48% of all babies are born left handed, by adulthood there are less than 15%.
Therefore at least 33% of all shooters will probably have a master eye problem,
to a greater or lesser degree. Eye dominance can change as well, due to,
tiredness, ill health, age, damage to head or eyes, or even to the type of
employment, sitting in front of a computer for long periods, this could account
for up to 20% of right handed and right master eyed shooters having a master
eye problem. Your master eye, for a lot of shooters, does not mean either left
or right eye dominant. you could have central vision, left  central or right
central vision, all of these problems will more than likely affect your shooting.