R.C.
I have a Medela Pump In Style and I was able to simply remove the actual pump apparatus from the bag. It is attached to the bag with velcro and it is approximately 4x4x4 cube Then, I put the pump in my carry-on bag, along with the tubing and the other pieces in a plastic bag. Yes, they do notice it when it goes through the x-ray machine and may ask a question or two, but in my experience, the TSA is very familiar with breast pumps.