Travel / Storage Stacking Tube

My wife wanted something for business travel that stayed well within TSA volume specs for various creams/lotions/meds... etc. I remembered the stacking, screw-together tubes we used to get in the fishing supply section of the local hardware store. Here is a version. The threads are all rounded to not require direct support, if you print it thread side down, the only support needed is minor on the flat edge only. The ones in the picture are an earlier prototype (hence the sanding and friction marks. The latest design has a bit more clearance and screws together much easier. I didn't photograph them before my wife took them on her first business trip.