Pen storage system. Requested for a family member, who didn't want individual holes for the pens.

Holds 36 pens per unit depending on pens (12 x 3 rows)

Base (wedge), to tilt the unit backwards to help pens stay in unit.

Top unit has flat top 

Print as many middle units as you need.

The units slide and lock together to produce a tower.

Units are 136w x 39h x 128d

Locking points may need a little filing with a triangle needle file.