Swarovski TLS APO 23mm Telephoto Lens System for ATX / STXThe Swarovski TLS APO 23 for ATX STX STR Spotting Scopes is an adapter used to connect a mirrorless system camera to the eyepiece module of your spotting scope. The 23mm version more closely matches the circle of illumination to the size of the camera's sensor. This concept makes Digiscoping a breeze so you can take professional grade photos of subjects at great distances with your choice of camera. To complete the system, you also are required to