LEGO Duplo - Ball Tube Cover Ring Top 40711pb01 Red - DECOTOYS
Amazon.com: LEGO Education Tubes Experiment Set with Storage 9076 : Toys & Games
LEGO PART 25214 Brick Round 1 x 1 diameter Tube with 90 Degree Elbow (2 x 2 x 1) and Axle Holes (Crossholes) at each end | Rebrickable - Build with LEGO