Fisher Space Pen gel conversion : r/pens

Fisher Space Pen #400H-237 / Tungsten Cerakote Bullet Space Pen

Laura's Five Favorite Fountain Pens -- $50 & Under. ( A Beginners guid - Pen Boutique Ltd

Pocket Pen Roundup — The Pen Addict

NPD finally got myself a nice pen (Zebra F701) but the refill sucks, any recommendations? : r/pens

Kaweco Sport Rollerball + EnerGel : r/pens

Pressurized refills

Fisher Space Pen SPR1, Refills for Bullet, Blue, 3 Piece

Fisher Space Pen pressurized refills (PR series) fits the following space pen product categories: Bullet, astronaut, shuttle, x-750, space-tec, military, zero gravity, futura, cap-o-matic adapters available to fit parker style pens. Blister carded for peg board display.

Fisher Space Pen SPR1 Refills for Bullet Fisher Space Pen, Blue,3 Pack

Parker Fountain Pen Twist Converter - Goldspot Pens

Monteverde Capless Ceramic Gel Parker style Ballpoint Refill - Extra F - Pen Boutique Ltd