mesh not visible upon rotation

HI
my mesh is not always visible. When I turn head(cam) it's not visible anymore until I turn back.
Thanks

 

This sounds like a backface culling thing. All meshes are rendered as single face.

You have three options; Sandwich two meshes back to back, find a two sided shader to render the back side or, add a script on object to rotate to always face the camera. The last option may not be appropriate in many applications.