The Smart is made with TPE, which is a synthetic blend somewhere between jelly and silicone. It is semi-porous and phthalate and latex free. It is very soft and flexible. The exterior has a somewhat sticky feel to it, which is actually not so bad because it allows you to keep a nice grip on it (as long as you don't get lube on your hand). The nubs on the inside give a nice sensation that is distinct from how your hand feels in a basic jerk-off. There is a bit of that synthetic smell some toys have, but it is not overwhelming or distracting.
The Smart is not as thick as many other penis sleeves, but its lack of girth does not detract from the feel. Because it only opens at one end, it creates a vacuum around the penis which produces a sucking sound that makes it easy to imagine you are receiving a blowjob. It is very compact, so it will easily fit in any bag. Because of the tower of nubs, it also has an interesting appearance that does not scream out sex toy. However, it is an object of curiosity, so if anyone sees it, they will want to figure out what it does. If you want discretion, don't leave this one out in plain sight because you will get some questions.
The Smart is best cleaned with soap and water. It flips inside out easily, so you can give it a thorough cleaning. Do not try to sterilize it. With this material, you can use water-based or silicone lubes. Store it away from light and dust and where it is not pressing up directly against other toys. It will fit nicely in any drawer or toy chest.
The box is simple, but its biggest advantage is that it is not much bigger than the toy itself, so you could actually store the Smart in the box. It has a diagram of the toy and some text, but almost everything is in Japanese. There a is a bit of English, but you have some translation issues, like where the Smart is described as a "function pursuit hole" Since most people will have no idea what that means, the box, like the toy itself, will prompt more questions than knowing looks. Just don't give people too much time to figure it out. The box does talk about feeling "Olgazm", so that might blow your cover.
The nubs are what really make the Smart stand out. And, don't limit yourself to just moving it up and down the shaft. Try twisting/rotating it around the shaft as well. That tightens the material around the penis and really emphasizes the nub effect.