I have already had several Moor hot water bottles from other manufacturers. This time I opted for this inexpensive product and even the same acquired two hot water bottles, as we do not find this in France. Unfortunately, the material is significantly thinner than the other products that I knew. Heating in the microwave, even at low speed and only 3 minutes brought the part by about 10 times, use almost explode. The same result with my daughter, who got the second Moor hot water bottle and another has microwave. Can one therefore probably only heat in the waterbath, which is not interesting for us. Can not recommend this product for Microwave fans.