The Alpine Astronomical Baader 1.25" to 2" ClickLock Expansion Adapter allows you to use larger 2" eyepieces in the more common 1.25" size holders. It has a standard 1.25" nosepiece, with a 2" ClickLock holder on the other side. This unique eyepiece mounting system is superior to conventional mountings. Unlike compression ring and set screw holders, the ClickLock system uses three long roller bearings to hold the eyepiece firmly centered in place without marking or marring it, while eliminating wobble and off-axis tilt that may occur with ring & screw systems. A simple 20° twist locks and releases the clamping system for fast eyepiece changes even while wearing gloves. There is no need to fumble with small set screws or for using excessive force and torque to hold the eyepiece in a fixed position.

The 1.25" nosepiece may be removed to expose an internal T-2 photo thread, enabling connection to other Baader Astro T-2 accessories. Also, the T-2 threaded ring may be removed to expose a 2" Schmidt-Cassegrain telescope (SCT) thread.