Includes 3- CR2 batteries The Snuza Hero is a compact and portable baby monitor that clips onto your baby's diaper. Babies are “abdominal breathers,” and Snuza Hero monitors your baby's slightest abdominal movement while they sleep and will alarm you if it stops. Simply switch on, clip on and start monitoring. It's lightweight, easy to use and fits in the palm of your hand. Dream on with Snuza Hero. Wearable & portable baby monitor that easily clips onto your baby's diaper or elasticized pants. Snuza Hero SE monitors your baby's abdominal movement and will vibrate to soothe your baby after 15 seconds of no abdominal movement. Snuza Hero SE will alarm after 20 seconds of no movement allowing you to check the reason. Heading out? Simply pop the Snuza Hero SE into your bag - no cords or complicated sensor pads needed. No need to hover over your sleeping baby. Enable Snuza Hero SE's audible tick mode to 'hear' your baby's abdominal movements while they sleep.