The bioresonance energy in the cushion lasts indefinitely - it will never expire, nor does it need to be replenished in any way. When lying directly on the cushion, you can expect your pet to feel the benefits of the calming energies emanating from the material, anytime, everytime. Our cozy cushion is suitable for pets of all sizes, breeds, ages, and temperaments and you can place it inside of any pet carrier, on top of your pet's favorite bed, on a sunny windowsill, anywhere your pet likes to hide when guests come over or the weather is wreaking havoc on their emotions.