Lightweight and rust-resistant material - Made from a lightweight aluminum alloy, this coaxial eyepiece lock adapter is designed to resist rust and withstand outdoor astronomy adventures. Stable coaxial connection - The coaxial quick-lock mechanism provides a secure and stable connection between your eyepiece and telescope, helping reduce interruptions and improving your observing session. Secure installation with non-slip gasket - An integrated anti-slip gasket ensures a reliable fit, keeping your accessories firmly in place so you can focus on your observations. Adjustable size options - Available in three sizes to fit different telescope configurations with M42 threads or eyepiece drawtubes, ensuring a proper fit for a range of setups. Use scenarios - Field observing with different eyepieces and telescope types, where quick and secure attachment is beneficial. - Routine observing sessions that require stable alignment and minimal drift during focusing. - Travel or outdoor observing where a robust, easy-to-install adapter adds reliability and ease of use.