I got replacement feet for my subwoofers that were made of really soft rubber. They work really well. This contraption seems to be a bit much though. If you’re looking at isolating your subwoofer from the floor, try the " SVS SoundPath Subwoofer Isolation System, 4-Pack" for $49.
With that said, I wonder if this stand or whatever you would call it is any better/worse.
I just received these yesterday and installed them to both a 10 " Mirage subwoofer and the taller option to a B & W center channel speaker. Gave them a test run watching Extraction on Netflix. I noticed an immediate improvement to what I had prior. I can’t say how they compare to the competitions offerings , but they are on sale here right now at half price compared to any audio retailer.