Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: Can I use it with a case on my iPad?
Document: It works about as well as I expected it to, increasing volume only about 20%, I would say. It would be nice if it attached more securely onto the iPad... although I use it while my iPad is inside the case. The price is definitely a good value; I purchased two of them @ $6.85 each!
The Pros, It makes your iPad about 50% louder, but its small & very light. It uses no electricity and doesn't use magnets or glue. Instead, it's just leverage.The only negative it that I don't think it fits great on my iPad with the case. My case is thick around the edges but it does it.Still, I would recommend this to anyone with an iPad. At 6 bucks what can you lose?
Works well. Does not fit real snugly with the iPad case I have, but does do what it is intended to do.
This sound amplification device works really well. It is redirecting the sound back at you. I wish it would fit on the iPad with the outer case on it but understand why it cannot.
A simple piece of plastic makes a dramatic difference in the volume! The amplifier even fits my iPad in its plastic case (I doubt it would fit every case, but mine works). I love a simple solution like this!
This little thing works great. I use it when watching videos on my iPad. It helps with the volume issues I was having and amplifies quite nicely.
I use this every day on my iPad 2 when I listen to YouTube videos and Netflix movies. Great buy, must have item.
I use my iPad as my "TV" near bedtime, and this now makes it even better!A must buy for all iPad users. (Except iPad Gen 1)
I was looking for something simple to help the sound carry on the iPad. The concept of this design is simple, but the problem lies in all the different cases that the iPad has and how this design will not accommodate any device that covers the back of the iPad. The obvious answer is to get an external speaker system, but this is not easy to carry around. It works as it's states but not practical for my use.
This is great to direct the IPad sound forward toward the user. Our toddler uses it often for meals out and in the car on the the headrest mount. It has made a significant improvement in not having to listen to his games/movies when sitting across the table from him or in front of him in the car. I would recommend this to anyone and prefer it over headphone use so I can still monitor what he's doing without having to see the iPad
Answer: I use the Bear Motion leather case with my iPad 4. It will slip on about 3/4 of the way befor the case stops it. In this position it does almost as good a job amplifying sound as it does when fully seated on the iPad. However, it can only be fully seated with the case removed.