AC Infinity AI-MPF140A MULTIFAN S4 140mm Quiet USB Cooling Fan can be positioned to stand upright or laid flat to cool various electronics and components. Features a multi-speed controller with power switch. Includes eight large anti-vibration rubber feet and a 6-foot power cord. The USB plug can be plugged into the USB ports found behind popular electronics such as receivers and video game consoles. Each unit contains an additional USB port, up to four fans can be daisy chained together to share the same power source.
 This fan system is CE and RoHS certified and contains premium dual-ball bearings, allowing it to be mounted horizontally or vertically. Contains AC Infinity axial fans ACX-FD1425(B)05W3 which meet UL-507 standards for safety under Underwriters Laboratories certificate E503903.

Features:

• Ultra-quiet UL-certified USB fan designed to cool various electronics and components.
• Features a multi-speed controller to set the fan's speed to optimal noise and airflow levels.
• Dual-ball bearings have a lifespan of 67,000 hours and allows the fans to be laid flat or stand upright.
• USB plug can power the fan through USB ports found behind popular AV electronics and game consoles.
• Fan Size: 5.5 x 5.5 x 1 in. | Airflow: 57 CFM | Noise: 18 dBA | Bearings: Dual Ball

For electronics and components that requires more airflow; each fan unit can daisy chain additional MULTIFAN S series fans. Up to four fans can share the same USB power source; and up to six fans can share the same thermal controller (sold separately). MULTIFAN S1, S2, S3 and S4 contains one fan, and MULTIFAN S5 and S7 contains two fans.