NinjaTek produces high quality flexible (Ninjaflex) and semi-flexible (Semiflex) 3D printer filaments. The Ninjaflex filament is a rubber-like, elastic filament. It is a more advanced material taking more effort to understand and cannot be printed in a bowden system, but is very suitable for applications where a lot of flexibility is required. Cheetah is a bit less flexible and serves a different range of applications.