Soldiers from many armies, especially in the special forces community, decorate their vehicles with different insignia; among them, skulls are one of the most typical.
Also, they are a symbol that can be used in historical and fantasy dioramas and vignettes.
These stencils include different variants of skulls, as well as skulls and bones, so all your needs will be covered in case you want to paint one on a model.
Just pick the stencil you want to use, hold it in place using masking tape, and spray paint or paint using an airbrush.
We have to prepare each shipment individually as they are ordered, so allow it in 3-4 weeks to arrive in the USA/Canada (to be safe) and 3-6 weeks rest of the world, though they are usually delivered much faster.