Crenova 3d Printing Pen Stereoscopic Craft Drawing Pen Printing Doodler with LED Display ABS or PLA Filament Material (Blue) Super energy-saving when standby and materials saving when using Freely control the speed and size of filaments outputing, drawing amazing 3D painting Press forward or backward button to insert or withdraw the filaments at anytime Free temperature adjustable buttonAdjustment by digital dispay, PLA, ABS and other materials are all suitable for our pen Done the adjustment only with one hand , No gear limited an adjust freelyNo limited speed