For our tests, we received both the NF-A12x25 G2 PWM and the NF-A12x25 G2 PWM Sx2-PP (dual setup fan setup) products. There is also a low PWM version called NF-A12x25 G2 LS-PWM if that interests you.

Starting with the "normal" version of the G2 series, the NF-A12x25 G2 PWM, the retail design is according to what Noctua has used also in the past with their distinct colours and overall design. There are several logos at the front and much performance information at the back.

Opening the retail package, you will find a 120mm fan and a box of accessories inside.

Inside the accessories box you will find

• NA-RC7 Low-Noise Adaptor (L.N.A.)
• NA-YC1 4-pin PWM splitter cable
• NA-EC1 30cm extension cable
• 4x NA-AV2 anti-vibration mounts
• NA-AVG1 anti-vibration gasket for water cooling radiators
• Fan screws

The fan itself has the usual 120x120x25 mm dimensions and includes a 4-pin PWM with a 20cm + 30cm NA-EC1 extension cable option. The fan includes SSO2 bearing technology and a new design, which, according to Noctua, offers better performance/noise ratio compared with older designs and other manufacturers. The normal rotation speed is (+/- 10%) 1800 RPM, while with the included L.N.A. adapter, it can drop down to (+/- 10%) 1500 RPM. The performance numbers that Noctua provides are very good, with airflow 107.3 m³/h (L.N.A. 87.2 m³/h), acoustical noise 22.5 dB(A) (L.N.A. 18.1 dB(A)), and static pressure 3.14 mm H₂O (L.N.A. 1.71 mm H₂O). The product includes 6 years of warranty.

At the top, there is a Noctua logo printed.

While at the back, you can see the blade's design. The NF-A12x25 G2 features a unique Progressive Bend impeller with Flow Acceleration Channels and winglets. Whereas the NF-A12x25’s nine impeller blades are bent relatively continuously, the NF-A12x25 G2’s blades are swept backwards close to the hub and progressively bent forward further out, which results in a distinct, almost kink-like shape. Noctua offers a long technical paper on its blade design that users can read and understand more about the overall philosophy and design. The retail price of the NF-A12x25 G2 PWM is EUR 34.90 / USD 34.90 and can be found at most Amazon worldwide stores.

Passing to the NF-A12x25 G2 PWM Sx2-PP, we will find two 120mm fans that are offset in speed, which can be beneficial in push-pull operation as well as in situations where two or more fans are operating side by side, such as in case cooling applications or on 240 and 360mm water cooling radiators. When two fans are running at almost the same, constant speed in a push-pull configuration or, albeit to a lesser extent, side by side, their acoustic interaction can lead to undesirable harmonic phenomena such as intermittent vibrations or periodic humming due to interference, which can be heard as beat frequencies. Therefore, the two NF-A12x25 G2 PWM fans contained in the Sx2-PP set are slightly offset in speed (+/- ~50rpm) to avoid such phenomena. 

The accessories box includes many goodies

• NF-A12x25 G2 PWM PPA
• NF-A12x25 G2 PWM PPB
• 2x NA-RC7 Low-Noise Adaptor (L.N.A.)
• NA-YC1 4-pin PWM splitter cable
• 2x NA-EC1 30cm extension cable
• 8x NA-AV2 anti-vibration mounts
• 2x NA-AVG1 anti-vibration gasket for water cooling radiators
• Fan screws

The fans have standard 120x120x25 mm dimensions and a 4-pin PWM with a 20cm + 30cm NA-EC1 extension cable option. The fan includes SSO2 bearing technology and a new design, which, according to Noctua, offers better performance/noise ratio compared with older designs and other manufacturers. The normal rotation speed is (+/- 10%) 1800 RPM, while with the included L.N.A. adapter, it can drop down to (+/- 10%) 1500 RPM. The performance numbers that Noctua provides are very good, with airflow 107.3 m³/h (L.N.A. 87.2 m³/h), acoustical noise 22.5 dB(A) (L.N.A. 18.1 dB(A)), and static pressure 3.14 mm H₂O (L.N.A. 1.71 mm H₂O). The product includes a 6-year warranty.

The two fans have different tags at the back, indicating the PPA / PPB tag to separate their minus 50rpm operation.