1.25" Astronomical Telescope Collimation Eyepiece for Refracting Telescopes

Used to calibrate the optical axis of a refractor , put the collimation eyepiecre into the tube. 1.25 inch calibration eyepiece is of short size , made of aluminum alloy. A wonderful accessory for both photography and astronomy lovers. Please adjust the screw if it is not in the center , in this way , you will collimate sucessfully. Make sure the black spot is in the center of 2 lines of collimation eyepiece.