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ARCTIC S4028-6K - 40x40x28 mm fan, 250-6000 RPM, PWM regulated, 4-pin connector, 12 V DC - Black : Amazon.co.uk: Business, Industry & Science
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Noctua NF-A4x10 FLX, Premium Quiet Fan, 3-Pin (40x10mm, Brown) : Amazon.co.uk: Computers & Accessories
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I wanted to upgrade my stock part cooling fan to a pair of noctua 40mm fans and when I did a test run they barely push any air through the ducts compared
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