ATARAXIA ART Flexible PLA filament, 3D Printer Filament,1kg, Better Than TPU, 89A Shore Hardness, Patented Formula, Compatible with Bowden Extruder, With Filament storage Bag, Pantone Match, PLA BROWN - Walmart.com
extruder - Filament isn't going into the Bowden tube, instead it goes "into the room" - 3D Printing Stack Exchange
How to 3D Print with Flexible Filaments - Gyrobot Ltd - CAD Design and 3D Printing