Element Type
You can choose between 2 different finite Element Types in the Mesh Settings 
dialog:
- 4 noded tetrahedron
- 10 noded tetrahedron (has midside nodes)
- Mixed 4 noded and 10 noded tetrahedron (hybrid mesh)
- See the Hybrid Mesh topic for more information.
- Regions of interest must be specified first with the Define Higher Order Regions
option.