Hardware Spec Index

Zephyra FN-3991 Pro 120mm PWM Case Fan

Case Fans · Zephyra · SKU FN3991-PRO · Released 2019 · Updated 2026-10-22

Key facts

Benchmark index413 (Case Fans scale)
Category rank#8,091
Street price$9
Power3 W
Performance per dollar45.89
Released2019

Specifications

BrandZephyra
ModelZephyra FN-3991 Pro
Size120 × 120 × 25 mm
Speed300–1,700 RPM (PWM)
Airflow57.8 CFM
Static pressure1.87 mmH₂O
Noise35 dBA
BearingFluid dynamic bearing
Connector4-pin PWM
Rated lifetime50,000 hours

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Cite this page: Hardware Spec Index, “Zephyra FN-3991 Pro 120mm PWM Case Fan”, https://vextor7.com/item/63318045 (accessed 2026-10-22).