ResinTech MBD-35 is a 2:3 volumetric mixture of CG8-H-ID (a dyed hydrogen form cation resin) and SBG1P-OH (a hydroxide form type 1 porous strong base anion resin). The cation component is infused with a permanent pH indicator dye that changes color from royal purple to amber as the resin exhausts. MBD-35 is intended for use in cartridge applications where a color indication of resin exhaustion is desired.