 Ready-made models (desk-top models) include those produced in fiberglass for travel agents and aircraft manufacturers, as well as collectors models made from die-cast metal, mahogany, resin and plastic.Generally known collectively in all its forms as the sport and pastime of aeromodelling, some flying models resemble scaled down versions of full scale aircraft, while others are built with no intention of looking like real aircraft.There are also models of birds, bats and pterosaurs (usually ornithopters).