On Amazon:
https://www.amazon.com/Sunflair-Water-Pasteurization-Indicator-WAPI/dp/B00F7104EY/ref=sr_1_1?keywords=wapi&qid=1666627711&qu=eyJxc2MiOiIxLjcyIiwicXNhIjoiMS40NSIsInFzcCI6IjEuNTEifQ%3D%3D&sr=8-1
On Ebay (Cheaper)
https://www.ebay.com/itm/115355832926?hash=item1adbbe525e:g:yFMAAOSwyV1iVeUM&amdata=enc%3AAQAHAAAAsAqL2SUEgxy9JH2fcxiU7zDKgW47mjuGxqXe93RPDdtm9MidIMkftwDZ32%2BPYN%2Fye%2B04fhIR1UN4i0y76CKOb7%2BzXM2jbXUZqI93McxJidY3FMsmjHj93Jz9lBw3oqjTmKu3nHY4B4GzB4rYovMqiaB24OfjTZy8%2F%2FSrQ3I5O0RZj6%2FoF0uzetqjRDVa5ubK4ozVVUzsnBFZFcY5RguFdDWiADg8mldAaXLBiumi55Wx%7Ctkp%3ABk9SR9rUkayBYQ