This case has nine external 5 ¼” bays. The bottom six comes with two hard disk drive cages, so each cage uses three 5 ¼” bays. The cages are fastened to the case using thumbscrews and can be removed or moved to a different position. Thus while the case comes with six internal 3 ½” bays and three external 5 ¼” bays (or two external 5 ¼” bays and one external 3 ½” bay if you use the adapter that comes with the case) you can have several different configurations. If you remove one of the cages, you have three internal 3 ½” bays and six (or five, if you use the 5 ¼”-to-3 ½” adapter) external 5 ¼” bays. And if you remove both cages you have all nine (or eight, if you use the 5 ¼”-to-3 ½” adapter) 5 ¼” bays available.

If you don’t have an external 3 ½” device (floppy disk drive or memory card reader) you can install up to seven hard disk drives with this case (six on the cages and one on the 5 ¼”-to-3 ½” adapter).

Each cage has a 120 mm fan that glows blue when turned on with a speed control knob, plus a washable dust filter. One of the cages (the one shown on the pictures below) has a support for installing an extra 120 mm fan (doesn’t come with the case).

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Figure 13: Hard disk drive cage.

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Figure 14: Washable dust filter.

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Figure 15: Rear view, notice the support for installing an additional 120 mm fan.

Nine Hundred Two does not provide any screwless mechanism for installing drives.