I have a REMstar auto/aflex A series machine, and the mask that leaked and caused a hole in the cornea of my eye was a FlexiFit 407 nasal mask. I now use the pillows, and have not had anymore problems. Although, There is scar tissue over the cornea of my eye, and bothers when I rub it. I have not had any more problems since using the pillows, and would recommend them to prevent any eye injury.