Leisure Time Reserve Bromine Reserve Sanitizer is a water treatment solution or powder suitable for disinfecting fresh water in hot tubs and swimming pools. It comes in a 32 oz bottle and is an EPA registered product with the registration number 7364-30-41760. The product is designed to be an alternative to chlorine and is suitable for use in spas and hot tubs. The model number is 45300A and it is made in the United States.