Cooler Master's CK351 is a mechanical keyboard for gamers that features optical switches, but also a durable IP58 certified chassis and full backlighting.
We recently tested the CK530 V2 and CK550 V2 from Cooler Master, affordable and nice mechanical keyboards. This time we're going to try the CK351 from the same brand. If these keyboards are similar in appearance, the last one is somewhat different, especially in terms of the technology used for its switches which are optical here. This type of switch has some advantages that we will detail in this test, but the price is also a little higher for this model since the bill is $120. That said, this price remains contained compared to high-end keyboards that easily exceed $200. Let's see if the CK351 lives up to its promise.
Like its CK500 cousins, the CK351 is made of plastic, but it is decorated with a brushed aluminum plate. In addition to a more refined aesthetic, this gives it a better rigidity and the keyboard appears quite solid. Here in full 105-key format, the total dimensions are 44 x 14 x 4.5 cm.
This consequent height is fortunately compensated by a foam palm rest provided by the brand. This is a good point, but it is identical to those of the CK530 and 550 V2 and is marred by the same defects. It does not have a fastening system, is a little too rigid in use and we do not guarantee its durability over time. Still better than nothing, though, and it allows you to clearly raise your hands above the keys.
The CK351 stands out from its peers with an IP58 certification that protects it from dust and water. This obviously gives it a longer lifespan, as dust is a ferocious enemy of mechanical components, in addition to avoiding some inconvenience in case of glass spilled on the desk. Under the keyboard, an innovative element is also present: the cable can be slipped into a gutter to make it come out on the left or right side of the keyboard. A nice detail, even if we would have preferred a paracord cable, more resistant in the long term. The keyboard feet are retractable, but their angle of inclination is not adjustable.
Apart from that, we find the Cooler Master shortcuts that allow you to manage the backlighting of the keys "on the fly" on the F keys and thus modify the colors, the lighting effects and their speed. Similarly, the backlight profiles can still be saved on keys 1 to 4, which are adorned with a third function noted on the edge. The multimedia functions are integrated above the arrow keys on Delete, Insert, etc.
These shortcuts are available directly from the Cooler Master website, but the manufacturer's MasterPlus software is ultimately easier to use. It allows you to visualize the color and effect adjustments that you apply, in addition to the possibility of modifying the functions of the keys or assigning macros to them.
On this model, Cooler Master has not integrated simple mechanical switches, but optical versions. The key is activated when an element of the switch passes in front of a beam of light, while conventional mechanical switches are activated when two physical elements come into contact.
This difference offers some advantages: generally, optical versions are (slightly) faster, much more durable - in this case with a guarantee for 100 million activations, compared to the usual 50 million -, and do not need to be soldered to the keyboard's circuit board. This makes IP58 certification possible and allows the CK351 switches to be hot-swappable.
Our test piece is equipped with "home-made" red linear switches with a 4 mm activation stroke, a 1.8 mm activation point and a force of 40 g, slightly faster than the mechanical version of the red switches (2 mm for 45 g). Being hot-swappable, you can change all or part of the switches for other types proposed by the manufacturer: clicky blue or brown (which offer a tactile feedback and a stronger activation force at 55 g). A key extractor is included with the keyboard, if needed.
The typing is indeed lighter and faster than the classic red switches. This may bother some regular users, especially in office use, but personally, no problems were found and the experience remains quite similar. In reality, the typing is fast and precise, but it is accompanied by a marked resonance of the keyboard, as we had noticed on the other CK models of the manufacturer. The hollow chassis and the aluminum plate are probably responsible for this. It's a pity that Cooler Master didn't integrate anti-vibration foam inside, but this is usually reserved for high-end models (but not all of them...).
The CK351 is not perfect, but it has some good arguments to make. Its robust construction, IP58 certification (protection against water and dust) and switches guaranteed for 100 million activations should give it a good longevity. We also appreciate the typing quality and the velocity of the optical switches, the full RGB backlighting and the presence of a palm rest. The latter is however very basic and the keyboard does not benefit from more advanced features such as dedicated multimedia keys or a paracord cable. The resonance of the keyboard is also really marked and could bother the silent ones.