What clef for non-pitched percussion instruments?

Non-pitched percussion instruments, like cymbals, drums, cowbells, etc,, don't follow conventional pitch notation and the placement of such notes on a musical staff, so they lack proper clefs. Rather, non-pitched percussion notation involves an "X" for where the instrument will sound across the five-line staff and a vertical line next to it that serves as a time line to designate precise timing of their strike or sounding within the musical passage.