SXDOOL AUB0405HD 40x40x20mm 5V 0.30A 4-wire case fan

Compact 5 V case fan

The SXDOOL AUB0405HD is a 40 mm square fan designed for tight spaces in servers, network appliances and small-form-factor PCs. It runs on a 5 V supply and draws 0.30 A, making it suitable for low-power cooling duties. The 4-wire special plug provides speed control and monitoring without a standard PWM header.

Fits 40 mm mounts with a 4-wire lead

This unit slots directly into 40 mm mounting holes and has a 20 mm thickness that clears most low-profile brackets. The 4-wire special plug requires a compatible header or adapter; it does not fit standard 3-pin or 4-pin PWM connectors. Builders must verify header pinout before installation.

Replaces noisy 40 mm stock fans

It serves as a drop-in upgrade for louder 40 mm fans in 1 U servers, switch chassis or embedded boxes. The lower current draw eases the load on 5 V rails. The jump is worth it when the original fan uses a 2-wire or 3-wire connection and the board supplies a matching 4-wire header.