Optec-DSI 3.5x24tpi to Tネジ アダプター (19912)

Threads are cut clean and square, so the adapter screws onto my focuser without any wobble or play. It's exactly the right depth to reach proper back focus for my camera. No complaints here, this little piece does its job perfectly.

The threads on this adapter are machined perfectly—no wobble when attaching my filter wheel. Screwed on smoothly to my scope without any binding. Exactly what I needed to get my imaging train aligned.

Finally, a way to mount my guide scope without fighting thread adapters – this adapter threads on smoothly and the T-thread connection feels rock solid.