20mm Long 42mm Extension Tube (SFE-M42-020)

I was worried the male threads might be too short to grip properly, but they hold securely even with a heavy camera setup. The threading is smooth and precise—no wobble at all. Great for dialing in that perfect back focus on my planetary rig.

The female threads are deep enough to hold my camera adapter securely without any wobble, and the matte black interior cuts down reflections noticeably. Perfect for getting that extra bit of focus reach with my telescope.

The female thread is deep enough that my camera and lens sit perfectly flush with no wobble, and the 20mm extension gave me just the right spacing for closer focus on the moon. Fit on my scope’s 42mm threads was snug but not sticky, which is exactly what I wanted.