EZ-Read Poly Test Pens are quick and convenient to use to determine treatment level between 38 to 40 dyne/cm. This unique pen is easy to read. When the level of the substrate is below 38 dyne/cm the ink is not visible, greatly improving operator accuracy. This fast, easy to read pen is ideal in production situations for quickly determining if treatment is present. The EZ-Read Poly Test Pens are available in red or blue ink.