Yes, you are correct Kirk, but not all tubing works with a peristaltic pump. I got several types of fine tubing that just refused to move fluids at all using a peristaltic pump. This helped run up the cost to me, getting tubing.

You see, OD is critical to achieve proper "contact" with the pump rollers, and ID is critical for flow rate. Flexibility is also critical to allow the rollers to compress the tubing. So, I have piles of tubing but only one type that works.

Here are the specs on the one that works:

I have 3 rolls each of #13 and #16 which fit my flow ranges. I have 2 universal pump heads that will take sizes from #13 up and one that will take #16 only. And, BTW, the type of tubing that works will not work with any sort of pressure at all except mild backpressure. It will also not tolerate much over room temperature.