This is a little bit larger than I expected it to be, but not large enough that it is difficult to pack. This tube offers a lot of protection for a medium to large sized brush. The plastic seems a little thin, but since the "cap" is basically the full height of the tube the double walled construction proved to be very sturdy.
I used it with an Omega S10065 and the width was just about perfect with about an extra half-inch of height when the tube is fully closed. It is worth noting that this tube could hold a taller brush if you just don't screw it down all the way, there is enough friction to keep the cap from accidentally slipping down if packed in a crowded bag.
Overall if you have a brush you care about protecting while you travel you could do a lot worse than getting one of these tubes, they aren't expensive and will protect your brush very well.