Material: Lamb wool Size: 16x15cm (excluding ears) Important Reminders: Please follow the product manual instructions. When heating water, it is best to fill the bag to two-thirds of its capacity; it should not be overfilled and care should be taken to prevent burns; after filling with water, the lid should be tightly sealed, any water residue should be wiped off, and leakage should be ensured is not occurring. The jacket is detachable and washable