The Grey Pneumatic GRY-82023MD 1/2" X 23MM DP DUO SCT 6PT is a high-quality, low-cost telescope eyepiece. This telescope eyepiece features a dual-pupil design that allows you to see twice as much detail as a standard eyepiece. The Grey Pneumatic GRY-82023MD 1/2" X 23MM DP DUO SCT 6PT is also achromatic, which means that it has no color. This telescope eyepiece is perfect for use with telescopes that have a 1.25" barrel. The Grey Pneumatic GRY-82023MD 1/2" X 23MM DP DUO SCT 6PT is a high-quality, low-cost telescope eyepiece. This telescope eyepiece features a dual-pupil design that allows you to see twice as much detail as a standard eyepiece. The Grey Pneumatic GRY-82023MD 1/2" X 23MM DP DUO SCT 6PT is also achromatic, which means that it has no color. This telescope eyepiece is perfect for use with telescopes that have a 1.25" barrel.