The refills listed below have been tested, are easy to find, and are extremely affordable.
We are still ordering and finding more and more pens that perfectly work with our pen. We will update the list as we find more.
Pen Name/ Refill Name
•Avant Pen Refills (0.5mm)
•Bic Velocity Gel 0.7mm (Medium)
•Cross Gel Rolling Ball Refill 0.7mm
•Dong-A Fine Tech RT Pen (GRC-43 refill)
•Duke Rollerball Refill (Medium)
•Faber-Castell Ceramic Rollerball Refill 0.5mm
•Foray (Office Depot's Brand-USA) Replacement Refills
•Mont Blanc Fineliner Refills
•Mont Blanc Rollerball Refills (M) & (F)
•Monteverde Rollerball Refill (Mont Blanc Style Replacements)
•MUJI 0.5mm Refill
•Ohto Ceramic Rollerball Refill (C-305P, C-307P)
•Pentel ENERGEL BLN105 pen (LRN5 & LRN7)
•Pentel HyperG Retractable KL257 Series (LR7 & KLR7)
•Pilot B2P Bottle to Pen Gel Ink Pen Refill - 0.7 mm
•Pilot Frixion Ball pen BLS-FR5 (LFBK-23EF-B refill)
•Pilot G2 (America's #1 selling ink gel pen, 0.38, 0.5, 0.7, &1.0mm)
•Pilot G2 Pro
•Pilot G6
•Pilot Hi-Tec-C Cavalier (Same performance as Hi-Tec-C, but with more ink)
•Pilot Juice Gel Ink Refill (LP2RF, .05mm)
•Pilot Precise V5 RT/V7 RT, named Hi-tecpoint V5 RT/V7 RT in Europe
•Pilot Q7 Needle Point Refill 0.7mm (BLS-GCK-7 / LHKRF-8C7)
•Pilot V ball RT (BLS-VB5RT)
•Pelikan Roller Refill 338 Rollerball
•Schmidt Safety ceramic roller 888 Fine
•Schneider Topball 850
•Staples Classic Grip Pen 0.7mm Gel (#31581)
•TUL GL1 Gel Pen Retractable Needle Point Fine 0.5mm
•Uniball Impact RT 1.0mm Bold (Signo UMR-80)
•Uniball Signo RT Gel 0.38mm & 0.5mm (UMN-138)
•Uniball Signo (UMN-152)
•Uniball Signo 207 Gel Refill 0.7mm (UMR-87, UMR-85)
•Uniball Jetstream 0.7mm (SXR-7) & 1mm (SXR-C1)
•Visconti Rolling Ceramic 0.7mm (AA40)
•Waterman Rollerball Refill
•Zebra Sarasa Clip Pen Refill
•Zebra JF Gel Ink (JJ2; JJ15; JJZ15; JJ21; RJF5 pens)

(The listed refills above are sometimes re-named or re-numbered in different parts of the world by pen refill companies. We can't list every possible name change so we suggest you use the info above if your country/region calls the pens/refills something else.)

All brands, logos, and trademarks displayed and/or mentioned are used for informational purposes only and are sole property of each respected company and owner. No endorsement or ownership implied.