Best way to anchor interduct

[signal15]

I've got a bunch of 1.25" interduct.  What's the best way to anchor this stuff so the end won't pull back through a hole?  I'm bringing it up through the floor under a built in entertainment center, and just want to cut it off right where it pops up through the floor.  I just need to make sure it doesn't fall back down or get pulled back down.

 

[Del91574]

You should look into a box fitting on the end. If done correctly you'd be able to use a regular locknut and possibly a reducing washer.