Amazon.com : BIC Velocity Original Mechanical Pencils, Medium Point (0.7 mm), Assorted Colored Barrels, 4-Count Pack, Pencils for Office and School Supplies (MV7P41-BLK) : Office Products
What is a velocity ratio?
BiC Velocity Thick Large (0.9 mm) No. 2 Mechanical Pencil Thick Large (0.9 mm) 2 ea | Artist And Hobby Supplies | Festival Foods Shopping
Two pulley wheel system with information box for mechanical advantage and velocity ratio Stock Vector Image & Art - Alamy