Good quality - works as intended
If you’re looking at this thing, you likely have a need for a variable length extension tube. This one works great in the range it’s designed for.
Baader VariLock Extension Tube
Well thought out and designed. The best way I can think of to get a tube of exactly the length that I need. And, there is no wobble or looseness.
Nice piece of kit
This does just what I need it to, allowing precise adjustment of spacing between a coma corrector and my camera.