Alphacool uses pure copper for the NexXxoS ST25 slim radiators. The end chambers, the water channels and the cooling fins are all made of copper, a unique selling point worldwide. No other manufacturer relies on pure copper for all these components combined.
To maximize the performance of a radiator, Alphacool reaches deep into its bag of tricks. Copper is the starting point. With a thermal conductivity of 400 W/(mK) for copper compared to 236 W/(mK) for aluminium, the winner is clear. Alongside this is the special fin density. Alphacool is one of the oldest companies in the field of water cooling and has carried out countless laboratory tests. The result is a fin spacing of 15 FPI. This means that the air flow is only slightly obstructed as the air can pass through even without high pressure. However, the cooling capacity does not suffer from this, on the contrary. To use the airflow optimally, all cooling fins have small serrations. These are tiny flaps that guide the airflow in the desired direction and increase the surface area. In the case of radiators, they are barely 1 mm high, but still provide controlled air turbulence to increase cooling capacity and minimise airflow noise.
The ST25 slim radiators offer the ideal liquid cooling solution for Mini-PCs or SSF (Small Form Factor) systems. Due to the extremely flat design, the NexXxoS ST25 radiators are ideal for such small cases and due to the reduced size, they give you the extra space you need to work in the case.

Technical data:
LxWxH: 393 x 120 x 25.5 mm
Material: copper
Material outer housing: steel
Fins per Inch: 15
Threads: 2 x G1/4“
Thread size fan mounting: M3
Fan size: 120 mm
Fan slots: 3 single sided / 6 double sided
Model: 14354