In terms of size, they are a bit smaller as a pen, as thick (so they can be put in anywhere where space is a ballpoint pen) and have two round caps. The important input cap is made of thin plastic, but felt well worked "limp" robust.
I've already tried it on various devices. IPads, iPhones or more different Android tablets. On all of the pen actually works flawlessly. I am surprised at how well you can thus enter things. Even after the 10 or 12 characters has to the outside as you have to manage it. In addition, it has the great advantage by using the stylus that one. No fingerprints on the screen and thus eliminates the constant grooming The only negative is the following. On my iPhone is a screen protector that use probably a little more difficult.
