The classic design of this classic hot water bottle. Treating sore muscles, stress or cramps, arthritis, aches and pains, stiff necks, lower back pain, Gifts for women menstrual cramps, and other common aches and can also double up as a cold compress for a person with fever or to reduce swelling for minor injuries. Good Mother's Day gifts for mom. Thermoplastic material that is recyclable. Advanced thermoplastic holds heat longer than traditional hot water bottles with a cover, and also works as an ice pack, or cold water bottle. But please Caution: The hot water bottle rubber is not suitable for Microwave oven heating.