The other day I was taking videos of the FREE module to analyze in Tracker, I went up to 15 PSI like I had been doing, and I accidentally popped one…Fortunately it popped at the end so I could cut off the broken part and just make the whole module shorter. Though I didn’t finish the first dataset, I can still compare it to data from the shorter module and examine how length affects the range of motion.
8.5 in FREE module 
10 in FREE module