After following the instructions carefully, inflating the ball to a certain size, leaving it for 24 hours, deflating it and inflating it again, or something like that, I used the ball a total of about 11 times, if that, just sitting on it, using it as preparation for my birth in October. I bought this ball because it was advertised as 'anti-burst'. I was sitting on the ball, and I leant forwards while sitting on it, and the ball burst. I was lucky that I am not too far along in my pregnancy that I can still stand up without support, and I saved myself from falling, however, this product is DANGEROUS for a pregnant woman who may not have been able to keep her balance. I contacted the seller to ask for a refund or replacement, or at least an apology, and waited over a week for a response, and heard NOTHING back. I will be contacting amazon to report of this problem, and if I still hear nothing back I will contact trading standards.
It is very common for pregnant women to purchase exercise balls, but this product is clearly DANGEROUS, as it is falsely advertised as an 'anti-burst' ball. I am furious at the seller for advertising it this way, and not contacting me back.
Do not buy this product, and do not use this seller.