Update: thanks to commenters, here is a cheaper deal on the same item, $108 and free shipping with ebay plus:
https://www.ebay.com.au/itm/265981213805
** Should I update the title and link to this new deal? **
This product seems to be controversial…! It's a large heavy cooler for passive convection cooling or with some fan assist, maybe just a chassis fan. I was thinking the open Thermaltake cases would work well with it. Another approach (which I currently use) is to use a "normal" cooler but make it well oversized for the CPU/TDP and run the fan at very low speed, which is enough to remove the hot air from the fins but is still practically silent. A third approach is to buy a case which is itself the cooler but these are expensive. Also, passive cooling is really only viable for intermittent load, so cooling benchmarks with high sustained load aren't really telling the right picture. The high thermal mass of the heatsink will absorb the heat from a burst of activity and then dissipate it more slowly. If you need max cooling performance for a high performance CPU then none of the above is viable. That's my take on it anyway :)
— original below
The NH-P1 is Noctua’s first passive CPU cooler and has been custom-designed for fanless operation from the ground up: in enclosures with good natural convection, its six heatpipes and thick, widely spaced heatsink fins enable it to cool modern high-end CPUs with low to moderate heat dissipation completely passively.
Product info: https://noctua.at/en/nh-p1
$99 + delivery at https://www.scorptec.com.au/product/cooling/cpu-coolers-air/…
Was $69 at PCCG but sold out https://www.pccasegear.com/products/54591/noctua-nh-p1-passi…