Overview

The Cooler Master MasterBox K501L is an ATX mid-tower case aimed at entry-to-mid-level gaming PC builders. Its front panel features sharp-angled ventilation with integrated red LED lighting that glows through the front and I/O panel, giving a subtle yet aggressive look. A lightweight acrylic transparent side panel lets you showcase your components without adding much weight. The interior is spacious enough to accommodate standard ATX motherboards as well as Micro-ATX and Mini-ITX form factors. Cooling flexibility is a strong point: the front supports up to a 360mm radiator, the top up to a 240mm radiator, and the rear a 120mm radiator. CPU cooler clearance is 165mm, and GPU length clearance is 360mm (or 410mm without a front radiator). This makes the case suitable for mid-range builds that require decent cooling but don't need extreme dimensions. The market positioning is squarely at budget-conscious enthusiasts who want expandability without spending a lot.

Compatibility Guide

The case supports ATX, Micro-ATX, and Mini-ITX motherboards. The power supply is bottom-mounted and can accommodate ATX PSUs up to 200mm in length. CPU cooler height limit is 165mm, and GPU length limit is 360mm (410mm without a front radiator), so most mid-range GPU models and tower air coolers will fit. Fan mounting: front – 3x120mm or 2x140mm; top – 2x120/140mm; rear – 1x120mm. Radiator support: front up to 360mm (max thickness 50mm), top up to 240mm, rear 120mm. Standard drive mounts are available for 2.5" and 3.5" drives (details limited).

Product Info

The MasterBox K501L was released around 2019, with an original MSRP around $50–$70 (¥7,000–¥9,000). Currently, it's priced at ¥48,041 on Japan, which is significantly inflated due to limited availability; buyers should check alternative retailers or second-hand listings. Warranty is the standard 2 years from Cooler Master. In terms of market segment, this case sits in the entry-to-mid tier, offering essential features like red LED lighting and transparent side panel at a low cost, but lacking modern amenities like USB-C front ports or tempered glass.

Best Use Cases

First, it's an excellent choice for first-time builders on a tight budget. The spacious interior and straightforward layout make assembly easy, and the cooling options are flexible enough to upgrade later. Second, users who prefer a simple, non-RGB aesthetic with a consistent red glow will appreciate the cohesive look. Third, it's a great foundation for a low-cost build using second-hand parts, where the case price is a minimal part of the total budget. ## Alternatives
In the same price tier, competitors include the Fractal Design Focus G (mesh front panel, includes white LED fans, better airflow) and the Corsair Carbide 100R (steel front panel, quieter, but less airflow). The MasterBox K501L differentiates with its red LED lighting and acrylic side panel, but its stock fan count is limited (usually only one rear fan). Compared to the Focus G, the K501L has better radiator support (360mm vs 240mm), but the Focus G ships with two fans. Overall, if you want a simple, flashy case for a low-budget build and don't mind adding fans, the K501L is a solid pick.

Things to Consider

The biggest caveat is the inflated current price on Japan (¥48,041), which makes it a poor value compared to much newer cases. The acrylic side panel is prone to scratches and may yellow over time. The front I/O only includes USB 3.0 ports – no USB-C. Cable management options are basic, with limited tie-down points. If you plan to use a large radiator or long GPU, double-check clearance (GPU length clearance of 360mm is fine for most, but some extra-long cards may need the front rad removed). Also, the stock fan configuration is typically just one rear fan, so you’ll need to budget for additional case fans to achieve decent airflow.

Product Disclosure (Amazon)

  • Manufacturer: Cooler Master
  • Seller: TAISEI商店
  • Fulfilled by: TAISEI商店
  • ASIN: B00CY8RTHS
  • Note: This article covers a manufacturer-made product based on Amazon listing details.