All metal construction and anodizing aluminium process, durable for long time use.
M42X0.75 female thread on both sides.
Converts an M42X0.75 male thread to a M42X0.75 female thread.
Makes it possible to attach M42X0.75 male thread and M42X0.75 male thread accessories together. Such as, you can upgrade your R&P focuser by adding "Alstar 1.25" High Precision Double Helical Focuser" to the end of the R&P focuser, if there is M42X0.75 male thread on the R&P focuser. This adapter will play very important part in connecting "Alstar 1.25" High Precision Double Helical Focuser"and R&P focuser.
This is a very high quality anodized aluminum adapter.