Sound Screen (Dual Speed)The Sound Screen masks outside noise with a white noise that is similar to the sound of rushing air. Use it to mask noises such as conversations, typing, noisy neighbors, printers, copiers, and traffic. This Sound Screen is durable and reliable. It is ideal for the busy therapist's office or waiting room. Just plug the unit into a 110 120V AC outlet and set it at high or low speed. Rotate the top to raise or lower the volume. Sound Screen is self