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Black mid-tower case with mesh front panel, tempered glass side, three 140mm fans visible

Montech

Montech AIR 903 BASE (B) PC Case

SKU CH-SRVB-1N04G MPN AIR 903 BASE (B)

E-ATX mid-tower chassis with 51 % mesh ventilation, three 140 mm PWM fans, USB-C front port and room for 400 mm GPUs

  • Max graphics card length400 mm
  • Supported motherboard sizesATX / E-ATX / Micro ATX / Mini ITX
  • Dust filteringBottom / Top
  • 3.5-inch internal bays2
  • 2.5-inch internal bays5 (Maximum) (2.5 in SSD*3 are supported with E-ATX MB instal
  • Expansion card slots7

Model Base (Black)

  • Supports E-ATX and ATX motherboards for versatile builds
  • Mesh front panel delivers 51% ventilation rate for high airflow
  • Three pre-installed 140mm PWM fans provide strong cooling out of the box
  • Fits graphics cards up to 400mm length including RTX 4090 models
  • Front USB Type-C plus two USB 3.0 ports for fast connectivity

Case Capacity & Layout

The Montech AIR 903 BASE is a black E-ATX mid-tower chassis designed for high-airflow builds. It arrives with three pre-installed 140 mm PWM fans behind a mesh front panel rated at 51 % ventilation. The enclosure supports ATX, E-ATX, Micro-ATX and Mini-ITX motherboards and provides seven expansion slots.

Ideal Builders & Limitations

This case suits enthusiasts planning large graphics cards up to 400 mm long and 190 mm wide, plus 360 mm radiators in both front and top positions. CPU tower coolers up to 180 mm tall fit comfortably. Builders who need more than two 3.5-inch bays or who want a front panel without mesh should look at a different enclosure.

Deciding Specification

The maximum graphics-card length of 400 mm is the single figure that determines whether this chassis fits the intended GPU. If the card exceeds that dimension, the side panel will not close; if it is shorter, the case provides ample clearance for even the largest current models.

How it compares

Measured against everything we stock in Tower & Desktop PC Cases, at today’s prices. Recalculated every night.

Price $56.99
Cheaper than about 84% of the 1,468 comparable items (median $100.99).
Max graphics card length 400 mm
Typical for this category: the median of 894 items is 400 mm.

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Specifications

Product
Brand nameMontech
Product typeE-ATX Mid Tower Chassis
Product colorBlack
Storage
3.5-inch internal bays2
2.5-inch internal bays5 (Maximum) (2.5 in SSD*3 are supported with E-ATX MB installed)
Ports & slots
Expansion card slots7
Front panel ports1 x USB Type-C, 2 x USB 3.0, 2 x Audio
Size & build
Max graphics card length400 mm
Dust filteringBottom / Top
Fan mounting optionsFront - 3 × 120 mm / Front - 3 × 140 mm / Rear - 1 × 120 mm / Rear - 1 × 140 mm / Top - 2 × 140 mm / Top - 3 × 120 mm
Product dimensions18.82 in × 9.06 in × 19.41 in
Shipping weight8.39 kg
Package size554 × 533 × 292 mm
Compatibility
Supported motherboard sizesATX / E-ATX / Micro ATX / Mini ITX
Radiator supportFront - Up to 360 mm / Top - Up to 360 mm
CPU cooler height limit180 mm
PSU length limit240 mm
More details
140mm fans3

Other versions of this model

2 more in the same range

Questions about this item

Will a 400 mm long graphics card fit with a 360 mm radiator mounted at the front?

Yes, the case supports graphics cards up to 400 mm and a front radiator up to 360 mm simultaneously.

How many 2.5 inch SSDs can I install if I use an E-ATX motherboard?

With an E-ATX board fitted, three 2.5 inch SSDs are supported out of the five maximum bays.

What front-panel connectors are provided for a modern motherboard?

The front panel includes one USB Type-C port, two USB 3.0 ports and two audio jacks.

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