ballpoint pens work on the principle of gravity

Parker Jotter Retractable Ballpoint Pen, Medium, Stainless Steel with barrel, Colors May Vary (78033)

MPDP80 – Swirl Double-Ended Pen – 12 pack

MOMOJIA Pens,Pens Ballpoint,Metal Wood Roller point Pen Retro Fountain Pen Signature Writing Pen for Executive Office,Business,Women Men

University of North Carolina Tar Heels Translucent 8 Pen Set 2506

University of Iowa Hawkeyes Translucent 8 Pen Set 2539

Ancolo Personalized Pens Rollerball Pen Engraved with Your Message Name pens, Team Name, Phone Number For journaling and office writing – Perfect for Men...

Greeting Pen Christian Inspirational Pen Set with Soft Touch Coated Metal and Stylus 6 pack 36091

Greeting Pen Bible Verse Pens- Trust God/Fear Not/Cross (36069)

ZORZA 3Pcs Crystal Pen Gold Metal Ballpoint Pen with White Crystal Yellow Crystal Green Fluorite Healing Stones for Office School Gift

PlaqueMaker Customizable Wood Veterinary Pen Set with Maple Case (Animal Image)