Cross Selectip Porous Point Refill, Medium Blue (8441) We were America's first manufacturer of quality writing instruments, and that means that we've been making pens people use, depend on and enjoy for a long time. All Cross writing instruments are unquestionably guaranteed against mechanical failure, regardless of age. Should there ever be a problem, please call a Customer Service Specialist at 1-800-282-7677. Cross offers a wide range of ball-point refill sizes and colors; Selectip gel rolling balls, porous-points (felt tips), ball-points and document markers; 0.5mm pencil leads; specially formulated cartridges and bottled inks. Blue Ink Medium Point Authentic Cross Refill