Refills will help you save money over buying new pens, and are also fabulously eco-friendly so there really is no excuse not to refill! 0.5mm refills.
Pilot Automotive RNAB0BSJ7PJSL pilot frixion synergy clicker erasable, refillable & retractable gel ink pens, extra fine point, assorted ink colors, 5-pack
Pilot FriXion Ball Knock Zone Erasable Gel Ink Pen Review — The Pen Addict
Pilot FriXion Fine 0.5mm Erasable Rollerball Pen Refills BLS-FRP5, Compatible with The Pilot Frixion Ball and FriXion Clicker. - AliExpress
12 Pilot Frixion Ball Knock 0.5 Erasable Gel Ink Pens, Purple, Extra Fine Point Coloring Bible Study Journaling Planer Markers Highlighters
Pilot FriXion Ball Knock 0.5mm - Blue Black
Pilot FriXion Clicker Rollerball Pen Erasable 0.5 Fine 0.7mm Medium All Colours
PILOT FriXion Clicker Erasable, Refillable Retractable Gel Ink Pens Refill 0.5mm 0.7mm Extra Fine
Rollerball Pen Pilot Frixion Point Clicker 0.5 - Black
Pilot FriXion Ball Knock Retractable Erasable Gel Ink Pens, LFBK-23EF-R, 3-pack The diameter of a lead : Extra Fine Point 0.5mm, 3 Color Set Pilot Gel
Pilot FriXion Ball Knock Retractable Erasable Gel Ink Pens, Extra Fine Point 0.5mm, Black/Blue/Red Ink, 3 Pens & 9 Refills Value Set
Pen and eraser combined in one Special erasable ink Retractable version of FriXion Smooth gel writing Rubber grip
Pilot Frixion Clicker Retractable Erasable Rollerball, 0.7 mm Tip - Black/Blue/Red, Pack of 3
8ct Frixion Clicker Erasable Gel Pens Fine Point 0.7mm Assorted Inks : Target