Are you looking for a high performance DDR4 SO-DIMM RAM Kit?
Because I am currently reselling some parts that came from my DeskMini X300 kit, it is a Corsair Vengeance SO-DIMM DDR4 4000MHz CL19-23-23-45-1T 1.35v 16GB (2x8) kit, it is the only 4000MHz kit referenced in the official "Memory QVL" of the DeskMini X300 (reference: CMSX32GX4M4X4000C19), there are 0.5mm thick full copper heatsinks (and graphene coating) affixed to it, I was also with Thermalright AXP90-X47 (Full copper) and the additional thickness of the RAM heatsinks does not interfere (it is tight but it passes without worries) and the latter allow to maintain the temperature of the DDR4 chips below 45 ~ 50 ° C (depending on the ambient and without ventilation).
On the OC side (with a Ryzen 7 5700G), at a "stock" frequency of 4000MHz it can hold the CL17-17-17-17-34-51-1T latencies without problem, and at a stable maximum frequency with InfinityFabric synchro (1:1) I managed to go up to 4266MHz in CL18-18-18-18-36-54-1T latencies, these last RAM frequencies allowing to give a good boost of up to +50~60% in frames per second in certain games compared to Stock RAM like 3200MHz (afterwards I also had the Vega 8 OC iGPU @ 2.4GHz so that helped a little too).
In short, in case you are interested, I am getting rid of it for 70€ (around 75usd) the whole kit (the 2 RAM sticks) because I really have no use for it anymore (no more DeskMini X300, changed to X600 model so
) otherwise I still have the labels and their original packaging too.