The benefit of warmth gives your child great comfort for minor or bigger worries, aches and pains and help them fall asleep faster | Holds the heat longer than traditional rubber bottles, 6-8 hours for a whole night, the cover is removable and washable | Made of the highest quality ECO sustainable thermoplastic from 90% renewable sources and comes with two years water tightness guarantee | Certified by the very high British Standard BS 1970:2012, CE conforming according to the Medical Product Regulation 93/42 EEC Class 1 | Unlike many hot-water bottles out there, the ones from HUGO FROSCH are absolutely free of any harmful substance, Phthalate-free, odorless and recyclable