Product DetailsThe MULTIFAN S2 quiet USB blower can be placed on top of various electronics and components. Features a multi-speed controller with three-speed settings and off switch located on the cord. Six-foot power cord contains a 5V DC USB plug that can power the blower through any USB port. Includes four silicone fan mounts that are attached to the bottom of the blower to absorb vibrations and to reduce noise. Each unit contains an additional USB port, up to four blowers can be daisy-chained together to share the same power source. This fan system is CE and RoHS certified with a 67,000-hour lifespan and contains premium dual-ball bearings, allowing it to be mounted horizontally or vertically. Contains AC Infinity axial fans ACX-FBD1225(B)05W5 which meet UL-507 standards for safety under Underwriters Laboratories certificate E503903.Speed ControllerThe blower includes an in-line multi-speed controller with power switch to set the fan?s speed to optimal noise and airflow levels for various environments. Connecting Additional UnitsFor 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. MULTIFAN S1, S2, S3 and S4 contains one fan, and MULTIFAN S5 and S7 contains two fans.ApplicationsThis ultra-quiet blower is designed pull air from the bottom and push it out the rear. It is ideal for electronics and components positioned in a cabinet or rack with a limited clearance height. Popular applications include modems, routers, receivers, amplifiers, Xboxs, home theater, AV cabinets, and entertainment media centers.