The Wathai 40mm x 10mm Mini Fan with Speed Control is a 2-pack of small computer USB fans designed for efficient cooling. With a maximum rotational speed of 5500.0 RPM and an air flow capacity of 6.12, these fans are powered by 5V and feature a noise level of 25.0 dB. Made of plastic, these fans are compact in size and lightweight, weighing only 0.15 pounds. The package dimensions are 4.8x4.5x0.9 inches, making them a convenient and effective addition to any computer system for optimal cooling performance.