The 71-2230 Right Angle Eyepiece Fits the 71-2022 and 71-2024 Alignment Telescopes. This eyepiece allows the telescope to fit in tighter places and allows the operator room to view from the side of the telescope. The 71-2230 Right Angle Eyepiece does not have a provision for autocollimation. If autocollimation is required, you will need the 71-2240 right angle eyepiece.