We do not provide rubber hot water bottles which have a lower rubber content and are bulked out with chalk and other chemical fillers. These types of bottles are ineffective at retaining heat and wear out much quicker leading to leaking and bursting. This hot water bottle has a higher rubber content (56%) which has greater heat retention. That's why they're a little bit more pricey - but we've chosen a bottle that, with the right care and use will work safely for a longer period of time