This is a smooth plastic material. It has no smell, but I didn't taste it. It's very smooth and non-irritating. It is also waterproof.
The size is great for travel. You can toss this right into your travel bag or suitcase without any issues. I think you could actually hide this in your pocket. It's really quite cute. I have one that I didn't buy here, but it's the same brand, and I enjoyed taking it on my boyfriend's business trip with us.
The vibrations are in the tip, and can also be felt in the attachments. There are no speed controls, just on and off. I think the waterproof feature is the best thing, as well as the variety in attachments. It is waterproof, but I haven't tried it underwater, other than for cleaning. I didn't have any problems when I went to try it again. It isn't very noisy at all, so I think you could use it with out needing to worry about being overheard.
You can wash this with toy cleaner or soap and water, because it's waterproof. You can store it in any case you prefer. You could store it in its packaging (if you kept it), as it has spots for each attachment.
The packaging is not discreet but it was easy to open.