I have written long hours with my Uni-Ball Pure Malt ballpoint loaded with the
black and red refills in the S-7S series and recommend them to anyone using one
of Uni's compatible pens. The blue and green ink refills are also vibrant,
smooth-running and reliable. They will last until the final whisper of ink is
gone. If you are a Pure Malt user as I am, you will find that Uni-Balls'
SXR-80-07 series of refills work just as well as the S-7S series...plus there is
a 4th refill "holder" inside the Pure Malt that you can slip a spare into for
safekeeping until needed!