Aquarius, Microite, Mavello, Neptune, and Orion appeared as separate older-machine choices in the original selector but led to the same broad category. Do not infer one model's filter arrangement from another. Have the model label or a photo ready when you compare current H2 options with a specialist.
The older .1M M.T. filter was listed for Technos, Masterpiece, and Regency II. If that name appears on an old invoice or cartridge, it can help narrow down the machine family; it is not an H2 filter part number. Review the machine label before discussing an upgrade.
The .1M AlkaBlue and .01M UF for AlkaBlue were listed for the older AlkaBlue family. An H2 Series machine uses its own filter system, so compare the new ionizer itself rather than trying to match an AlkaBlue cartridge to it.
H2 Series replacement filters are designed for H2 Series machines. Do not order one for an older ionizer without checking compatibility with AlkaViva. There is no single H2 choice for every model in this group; installation, space, and preferred countertop or undersink arrangement all matter.