The NF-A4x20 5V is a special 5-V version of Noctua's highly optimised silent 40x20-mm premium fan, which uses the AAO frame system and advanced aerodynamic design measures such as flow acceleration channels. The Smooth Commutation Drive technology and the SSO2 reference class bearing guarantee excellent smooth running properties and excellent long-term stability. Modular cabling and the OmniJoin™ adapter set make the NF-A6x25 5 V a premium solution for demanding 5-V applications. CAUTION! The NF-A4x20 5V PWM is a 5-V fan and cannot be operated with 12 V. Operation using common 12-V power sources such as fan connections of PC motherboards will damage the fan. https://elecena.pl/product/18404613/nf-a4x20-5v-nf-a4x20-5v-fan-40-mm 2021-05-08 https://elecena.pl/product/18404613/nf-a4x20-5v-nf-a4x20-5v-fan-40-mm 2022-12-03