Cooler Master Launches MasterBox Q300 Line Of Micro-ATX Cases

Cooler Master added two new mini towers, the Q300L and Q300P, to its MasterBox series of cases. These cases are designed to be compact, non-restrictive, and transportable.

Since the original MasterCase series launched in 2015, Cooler Master has adopted a semi-modular design approach to many of its cases. Although not all of the products that bear the MasterBox or MasterCase name are totally modular like members of the MasterCase Maker series are, but they’re all designed with some extent of customizability. The new MasterBox Q300L and Q300P are no different. Looking at them side by side, it’d be hard to tell that the two are related at all, but the Q300P is actually just a pre-customized version of the Q300L.

Beginning with the cases’ external appearance, the Q300L (pictured above) is the more plain of the two. The case has patterned mesh panels on its front and top that are magnetically attached, while its bottom is covered by a plain mesh panel with rubber feet. The Q300P (shown below) has extruded acrylic panels covering its front and top instead. It also has handlebars at all four corners, negating the need for feet.

Because the Q300P’s overall form is larger, it can fit a decorative, RGB-lit accent panel at its top-front, which is controlled by an included RGB controller module. Strangely, this module allows you to rewire the case’s reset switch to toggle the lighting mode. Cooler Master’s guide for the controller doesn’t explain its lighting modes or compatibility with other lighting ecosystems, however. Getting back to the customizability element, the Q300L’s top mesh panel can be removed to fit a handlebar, making the case easier to transport. Similarly, the Q300P’s four pre-installed handlebars are removable.

As mentioned earlier, both cases are the same internally, so we can talk about their practical features together. Expanding on the customizability aspect, the Q300 cases have symmetrical side panels that allow multiple placement options for the side-mounted I/O module. It can be moved between the top, bottom, and front edges of either side. Inside, the Q300 case can fit a standard mATX motherboard, an ATX power supply up to 160mm in length, and graphics cards up to 360mm in length. The vertical clearance for CPU coolers and graphic cards is 157mm.

For cooling, the cases can fit either two 120mm fans or two 140mm fans and a 240-type radiator at the front, two 120mm fans without any radiator(s) at the top, one 120mm fan and radiator at the back, and one 120mm fan without a radiator at the bottom. Expansion-wise, the cases have four card slots and space for one 3.5” and two 2.5” drives.

Pricing and availability of the MasterBox Q300P and Q300L in North America is currently unknown. According to Cooler Master’s website, the Q300L can be converted into a Q300P with an upgrade kit.

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ProductMasterBox Q300LMasterBox Q300P
TypeMini TowerMini Tower
Motherboard SupportmATX, Mini-ITXmATX, Mini-ITX
Dimensions (W x D x H)230 x 387 x 378mm230 x 450 x 450mm
Space Above MotherboardUnknownUnknown
Card Length360mm360mm
Power Supply FormatPS/2 up to 160mmPS/2 up to 160mm
External BaysXX
Internal Bays1 x 3.5”, 2x 2.5”1 x 3.5”, 2x 2.5”
Card Slots44
Port/Jacks2 x USB 3.0, Mic In, Audio Out2 x USB 3.0, Mic In, Audio Out
OtherRow 11 - Cell 1 RGB lighting controller
Front Fans2 x 120mm or 2x 140mm2 x 120mm (included, RGB LED) or 2x 140mm
Rear Fans1 x 120mm (included, non-LED)1 x 120mm (included, non-LED)
Top Fans2 x 120mm2 x 120mm
Side FansXX
  • Lucky_SLS
    I like the design language of CM since it's inception of masterbox/case lineup. The Q300L is no different but can't say the same about Q300P.