A pH pen tester is handy tool that measure if a liquid are acidic or basic. This tool matter for lots reasons. Peoples use it in schools, labs, and home too. For example, gardners check soil pH to see if good for plants. And in labs, scientists test solution for experiment. SKZ company make high-quality pH pen testers that easy to use and very precise. If you looking buy pH pen testers in bulk, its important know what to look so you get the best one.