Fisher Space Pen SPR3 Pressurized Ballpoint Refill, Medium Point, Green Ink

Unlike ordinary ballpoint refills that rely on gravity and fail in extreme conditions, the Fisher Space Pen SPR3 refill uses a sealed, pressurized thixotropic ink cartridge. This design allows it to write at any angle—even upside down—underwater, over grease, and in temperatures from -34°C to 121°C. The medium point lays down a clean green line with fast drying and high smudge resistance.

Highlights

• Pressurized thixotropic ink writes in zero gravity, underwater, and on wet or greasy surfaces
• Medium point (M) for balanced line width
• Green ink for vivid, legible writing
• Operating temperature range: -34°C to 121°C
• Metal (brass) body for durability
• Fits all Fisher Space Pen models and other pens accepting SPR series refills

In daily use

Swap this refill into your Fisher Space Pen Bullet, Cap-O-Matic, AG7, or any compatible pen. The pressurized cartridge ensures consistent ink flow from the first stroke to the last, whether you're jotting notes in a notebook, filling out forms outdoors in winter, or writing on a vertical surface. The fast-drying green ink resists smudging and fading, keeping your writing crisp for years.

Full specifications

• Product Type: Pen Refill
• Refill Type: Ballpoint
• Ink Color: Green
• Point Size: Medium (M)
• Ink Technology: Pressurized Thixotropic Ink
• Writing Angle: Any angle (including upside down)
• Operating Temperature Range: -34°C to 121°C (-30°F to 250°F)
• Underwater Writing: Yes
• Writing on Greasy Surfaces: Yes
• Writing on Wet Surfaces: Yes
• Gravity Independent: Yes
• Compatibility: Fisher Space Pens (e.g., Bullet, Cap-O-Matic, AG7) and other pens accepting Fisher SPR series refills
• Refill Body Material: Metal (Brass)
• Quantity Per Pack: 1
• Model Series: SPR Series
• Ink Drying Time: Fast
• Smudge Resistance: High
• Fade Resistance: High
• Shelf Life: Long (sealed)
• Origin: Made in USA

Final note

One refill, endless reliability—from the depths of the ocean to the vacuum of space.