ballpoint pens work on the principle of gravity

12 Pieces Rolling Ball Pens, Quick Dry Ink 0.5 mm Extra Fine Point Pens Liquid Ink Pen Rollerball Pens Black

8 Pcs Blue Ink Ballpoint Pen with Stylus Tip 2 in 1 Stylus Ballpoint Pen Metal Pens Stylus Pen for Touch Screens School Office...

0.7mm Gel Pens Retractable Cute Black Ink Pens with Silicone Grip Smooth Writing Suitable for Note-taking, Sketching, Drawing (Gold Clip12 pcs)

12 Pcs Blue Ink Ballpoint Pen with Stylus Tip, 1.0 mm Metal Pen Stylus Pen for Touch Screens, 2 in 1 Thank You Pen...

TIESOME 6pcs Floral Art Ballpoint Pens, 1.0mm Fashionable Retractable Ballpoint Pen Black Ballpoint Personalized Pens, Suitable for Women, Colleagues, Teachers, Students Gifts(color2)

BIC Cristal Xtra Smooth Ballpoint Pen, Medium Point (1.0mm), Black, For Ultra-Smooth Writing, 24-Count

Paper Mate Ballpoint Pen, Profile Retractable Pen, Medium Point (1.0mm), Blue, 12 Count

Unibene Slim Metallic Retractable Ballpoint Pens – Matte Black & Silver, Nice Gift for Business Office Students Teachers Wedding Christmas, Medium Point(1 mm) 6...

BIC 751766084321 Cristal Xtra Smooth Pens Blue Medium Point. 10-Pack

Gel Pens, 0.5mm Black Ink Pens, Fine Point Smooth Writing Pens – Pack of 10, Bulk Ink Gel Pen, Fine Tip Ballpoint Pens, Rollerball...