Filter holder for blocking filter with M28.5×0.6 threads

• Front side – M28.5×0.6 female thread
• Rear side – M28.5×0.6 male thread

Machined from high quality aluminium alloy.

This adapter allows mounting a blocking filter from a Coronado BF15 diagonal anywhere in the optical train.

Front and rear threads are standard for 1.25″ astronomy filters. The blocking filter is held in the adapter by the retaining ring.