Neutral Litmus Test Papers are a quick and easy way to test the general acidity or alkalinity of a solution. These strips are coated with a special dye that changes color; simply dip one into the solution and it will turn red if acidic (less than pH 7.0) or blue if alkaline (greater than pH 7.0). Neutral litmus test strips are accurate, reliable, and easy to use, making them an essential tool for laboratories, schools, industry, and home brewing. Each strip measures 1.875"L x 0.25"W (48mm x 6mm). Vial of 100 papers.