In Japanese "Meiki" simply means Gorgerous or Superb. So in fact a Meiki Onahole or Vagina is supposed to be of high quality and very close to reality. The most popular Meiki Onaholes are made by NPG who has a long history of producing Meiki Onaholes, many of them based on popular Japanese Porn Stars but of course not all Meiki's are made by NPG, there are other makers as well. Examples for great Meiki Onaholes are Meiki 010 Okita Anri Onahole, Meiki 005 Chou Shuu U Onahole or Meiki 001 Maria Ozawa Onahole only to name a few. You can find a wide selection of them in here.
Recently many makes started to use the word Meiki for their products. Some of them are small and quite cheap and by using the name Meiki they can easy be confused with the high quality onaholes. As the word Meiki itself has no trademark on it, basically any masturbator or Onahole can call itself Meiki as it means nothing else then Gorgeous or Superb.