Shop our selection of Myron L Company Ultrapen Products and Instruments to quickly and accurately measure the quality of your water. Our selection features the Myron L Ultra TDS Pen that is easy to use in your hydroponic growing applications. Myron L Company is the leading manufacturer of pH instruments for a variety of different areas of the water quality control industry. Our Myron L Company Ultrapen Products are part of our selection of TDS Meters & PPM Meters, pH Meters, and other environmental control products. Choose from all of the popular brands and top products in our HTG Supply online store.