毫髮不爽 háo fà bù shuǎng

DEFINITIONS

  1. not to deviate one hair's breadth (idiom)
  2. to be extremely accurate

CHARACTERS

毫 háo fine hair; measure of length
髮 fà hair
不 bù no, not; un-; negative prefix
爽 shuǎng happy, cheerful; refreshing