Bluegears b-PWM 90mm Red with Red LEDs 2 ball bearing high speed high performance PWM technology fan. PWM Technology with mini 4 pin 4 wire connector to connect directly to the Motherboard fan connector for ultimate fan speed monitoring thru Motherboard. Extreme Speed range from 500 to 4000 RPM with Excellent Airflow of up to 88 CFM. 9 translucent Red blades design for ultimate airflow and low noise level at only 39 db. Mini 4 pin 4 wires connector with PWM fan speed signal output. Include a 3 to 4 pin Molex adapter for direct connection to Power Supply. 4 screws included. Customer Service: Supportatbgears.com or call 702-988-6808.