These collimation caps are a simple, portable tool for quickly checking and adjusting the alignment of your reflector telescope's optics.

Each cap is 3D printed from durable, environmentally friendly PLA polymer and has a highly reflective disc on the inside that makes it easy to use.Unlike other collimation caps, it has an ergonomic rim for easy removal.

The size is 1.25" and it is a universal snug fit.