This entry includes the two parts for the Rod model used in Part I of the cell size lesson. The top file should be printed with the open side facing down, and the bottom file should be printed with the open side facing up, this ensures that the models can be interlocked to obtain the complete model. 

Note: The lesson suggests including a nucleoid constructed out of monofilament fishing line, and a packet of 3 mm beads representing ribosomes.