Tele Vue Tunable Top with 1X adapter

The Tele Vue Tunable Top with a 1.25-inch Adapter (model #TE-ATT-2125) is the tunable top version of the standard 2-inch Paracorr Type 2. It lets the user position all eyepieces for optimum coma correction. For use on the BIG Paracorr, the "VISA" (Visual/Imaging System Adapter, sold separately) is required. A 3-inch Tunable Top is not required since secondary mirror size limits maximum exit pupil diameter to around 7 mm. Therefore, the widest true field eyepiece choice with an f/3 is the Tele Vue 21 mm Ethos eyepiece, which delivers a 6.1 mm exit pupil at f/3.45. To use the TE-ATT-2125 2-inch Tunable Top by Televue, just remove the stop flange from the Big Paracorr, attach the VISA adapter (TE-AVI-3200) adapter to the top of the Big Paracorr Type 2 and then screw the Tunable Top on top of this adapter. However, the Televue TE-ATT-2125 2-inch Tunable Top will attach directly to a 2-inch Paracorr. Then adjust the sliding lever on the side of the Tunable Top barrel to position your eyepie