Altair Astro can make a custom ERF holder to fit your telescope.
We need the following dimensions to design a custom ERF holder, or to check if an existing model will fit your telescope:
![Measure telescope to fit Altair ERF](https://www.altairastro.help/wp-content/uploads/2023/07/Altair-Custom-ERF-Telescope-Dimensions-info.png)
We need these dimensions to make you a custom ERF filter holder, or to check if an existing model fits your telescope.