Hyperboloid Pen / Pencil

A perfect gift for any math teacher- the precisely oriented holes in this base direct 16 pencils to reveal a hyperboloid, the 3D surface traced by revolving a diagonal(skew) line, the outline of which is the conic section of the hyperbola. A doubly ruled surface for any desktop!
This stylish pen / pencil holder is a great way to store your writing utensils. New Sizes Available! We have 16 and 25 Pen / Pencil holders that accept any pen, pencil, hobby knife or tool that is 8.5mm or smaller in diameter. Additionally, we have a 16 Marker holder that can hold Sharpie and similar diameter Permanent Markers that is 12mm or smaller in diameter. This product is 3D Printed and made to order. Please allow 1-3 business days for printing time before shipment. Pictures do not accurately reflect the size of this product! Please check dimensions listed below to make sure that this product will fit. *Pencils / Markers Not Included

Returns Accepted for this item if it's within 30 Days