Point group C3v - Dual extruder
"In crystallography, a crystallographic point group is a set of symmetry operations, like rotations or reflections, that leave a central point fixed while moving other directions and faces of the crystal to the positions of features of the same kind."
https://en.wikipedia.org/wiki/Crystallographic_point_group
This is a dual-extrusion model.
Trigonal cell.
Schoenflies notation: C3v
Hermann–Mauguin notation: 3m
Orbifold: *33
OpenSCAD files included to make custom cells.
Further information:
https://www.staff.ncl.ac.uk/j.p.goss/symmetry/C3v.html