3 Sound Options - Time-tested by the sound specialists at Marpac, these sound options promote sleep and mask noise: bright white noise, deep white noise, or gentle surf. Portable - Simply fasten Hushh to a stroller or car seat using the included baby-safe clip or place it on any surface. The simple interface is easy to use and operate with one hand. Child lock - Offers the ability to lock Hushh at a desired setting and volume to prevent younger hands from altering the sound or turning the unit off. Amber LED Nightlight - Provides just enough light to see by without causing wakefulness for parent or baby. Guarantee - Backed by a one-year limited factory warranty and the always exceptional Marpac customer service promise.