Quiet. Very quiet. Small for heatsink or tight areas

Can't think of any, been using it for 6 months now and still going strong.

Bought it by accident without paying attention to the size, but thought I'd play around with it's positioning withing my rig. Currently have it on my M.2 heatsink and it's keeping the SSD on average about 5-7℃ cooler than my other 2 I have. Originally put it on top of my RAM to try and cool them a bit as I have all 4 slots populated. But their current heatsinks do a sufficient job and didn't notice any performance improvements over the past month or two. The storage on the other hand can definitely benefit from additional cooling especially for those PCIe GEN5 drives that want to cook me dinner with their temps. I'll be adding 2 more onto my other M.2 drives I've got. It's very quiet, the quiets fan in my system and from what most others have said these smaller fans have a tendency to be noisy as they spin at such high RPMs. Mine runs at 5000 RPM all day, not sure where the 4000 RPM comes from.

Surprisingly quiet for the 40mm size.

Very small fan (used on chipset heatsink)