Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: How wide is the roller?
Document: This roller is very convenient to use and it does a great job of cleaning without any scratches. Love it!
This little roller is great . Cleans my phone or tablet in seconds. Fits right in my purse. Ready to use.
This is a great product. Very easy to use.Haven't had to clean the roller yet, so I can't say how well it wiil work after using running water on it.
i used this roller and it didn't clean my tablet at all. Waste of money. I know someone that has this and she loves hers but it didn't work for me. Very disappointed. I was looking forward to useing this but it didn't work for me. Tried a couple of times so now it's laying in the drawer.
After cleaning, my iRoller was good as new.You can carry the iRoller in a pocket or purse, or store it in a drawer, because the sticky interior roller is fully enclosed in a hard plastic roll-top case. The case opens and closes with a flick of the fingers.
It worked great when it arrived. Then I needed to clean it. The directions say that you should rinse it under warm water to clean the oils off of it. I've done so several times but it doesn't seem to get the original oils off of the roller and I end up just using a cloth to clean the smudges that this thing leaves behind.
This is a great little roller to clean your devices with. I love that you can clean it just by running it under some water. It does clean off fingerprints really well. Some of the older prints you kind of have to scrub a little, but this is well worth the money. Also, it fits easily in a purse or bag too. You can just tote it with you to work or school! It can even fit in your pocket!
The I-Roller screen cleaner is awesome. It does a great job of removing fingerprints and smudges on your Ipad and Ipod touch screens. There is no film left on the screen after using this like there is when using a micro-fiber cloth. I have let several family members use this and they all think it is great. Very easy to clean, just rinse under the faucet and let dry.
This little roller is amazing! It works with just one swipe. Cloth cleaners take a bit of rubbing back and forth. I cant wait to try it on my touch screen in the car. We have a cadillac SRX and I just hate the touch screen cause it always looks so filthy with finger prints. This little rooler will take them off in a nan-o-second. Just one roll....done!
I only bought this because it was an "add-on" so that my purchase would allow for free shipping,. I can say that when cat hair on my tablet or Kindle, this does remove it. However, it really does not remove finger smudges very well from mt tablet.The inventor of this product wrote to me to clarify that if I smear the old fingerprints with my finger the roller would remove them. I did this, and the roller does remove them,  So I increased my rating.
Answer: It looks like 3.75 inches for just the roller part.