Meade 16" SCT 4" 螺紋轉 Celestron 3.29" 螺紋轉接環 (19790)

The outer diameter is a beefy 4.45 inches, so it grips solidly in the visual back without any wobble. I swapped my eyepiece setup over in under five minutes and the threads engaged cleanly on the first try.

I was worried about thread compatibility between my gear, but this adapter fit perfectly—the 4.45" outside diameter gives it a reassuringly solid feel. No wobble at all once I tightened it down.

Finally having a solid way to attach my Celestron gear to the 16-inch SCT instead of relying on makeshift solutions. The 4.45" outside diameter feels substantial and the threads engaged perfectly on the first try.