Ceiling Vibration Damping Mounts, 8 Pack Spring Vibration Isolator Hangers, 110Lb Capacity, 1.2” Deflection Ceiling Spring Vibration Isolator for A/C Air Handler Home Theaters, Studios, Hotels

they are exactly as advertised

They were too stiff for my application, but that's not the reason for my rating. They're not built all that well for the weight they're designed to hold. I'd want something more substantial.

I'd been looking for something like these dampers for some time. I run propane heat in my workshop and the sound of it running is communicated thru the floor so installation of these dampers not only isolates the heater from the building but also minimizes wear and rear on the heater as well due to reduced vibration.

Supposed to be 3/8" rod not metric.. CHEAP CRAP

Barebones and basic, but functional. They seem fairly sturdy feeling, though the weld line on some of them don't look amazing. Most of them were good, but some of them just look kind of sloppy; I included a picture of one. Overall it's not bad, and it works, but it's not pretty and the quality control seems to be average at best.