Tele Vue Dioptrx 0.50 Astigmatism Corrector - DRX-0050 Tele Vue you may even forget that

you may even forget that you have an eyepiece between you and the universe

Focal Length: 20mm

and enjoy the fact that the extension is also threaded for a filter

Baader Dark Blue 435nm Bandpass Filter Features

Eyepiece diopter scales for sharp focus

Tele Vue Dioptrx 0.50 Astigmatism Corrector - DRX-0050 Tele Vue you may even forget thatTeleVue Dioptrx 0. 50 Astigmatism Corrector for TeleVue Eyepieces Got astigmatism? Get the "cure" Your telescope's focuser is used to compensate for your near or far sightedness; TeleVue Dioptrx compensates for your astigmatism. These units attach and lock onto the tops of over 20 long eye relief Tele Vue eyepieces to achieve the sharpest full field viewing possible. TeleVue Dioptrx models are available in . 25 to 3. 25 diopter (1 4 steps from . 25 to