Needed a refil for my Parker pen and, after reading a few reviews of various ones, I decided to give these a try.
They fit perfectly in the pen despite being a slightly different shape & size. Tried one the other night and got slightly frustrated at having to go over various letters again and again because the ink doesn't work all the time.
They are cheap and you get enough to last quite a while but after using one for an hour or so the other night, you get what you pay for. If your not too fussy about the quality of the ink being up to Parker standard then thy are OK, otherwise you get what you pay for I guess.