Turn any pet bed into a soothing resting spot! Help soothe and calm your new puppy or kitten with the melodic vibration of a mother's heartbeat. The ingenious design of the Mother's Heartbeat Puppy toy and Kitty Pillows create the soothing feel and sound of a maternal heartbeat. Pillows come in 3 different heartbeats per minute based on breed sizes. Plus one for kittens! Included with each heartbeat toy is a heartbeat device. Heartbeat device installs into pillow's zippered pocket. Batteries included. Based on estimated heartbeats of the breed of the parents and puppy/kitten. Small breed, up to 20 lbs. Medium breed, up to 80 lbs. Large breed, over 80 lbs. Kitten, 1 size fits all. One year limited warranty.