ResinTech MBD-15-ULTRA is a mixture of a dark-colored hydrogen form cation resin and a hydroxide form type 1 strong base anion resin. The resin ratio is 1:1 on an equivalent basis. The ULTRA grade means it has been functionally tested to produce > 18 megohm resistivity and under 2 ppb of TOC. MBD-15-ULTRA is intended for use in all mixed bed deionization applications that require high resistivity and high throughput capacity.