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 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. Included with each pillow is a heartbeat device. Heartbeat device installs into pillow?s zippered pocket. 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 (available in heart shape only) 1 size fits all . One year limited warranty.