So, I like cellphone cases. I like to protect my cellphone. It's all and well if you use the default battery size. For extended batteries, it's really hard to find cases that are made for them. 3rd party extended batteries differ in shape and size.I had a HTC Evo previously and I shelled out the money for a Sedio extended battery plus case, but they're expensive.With my Evo 3D, I decided to get a cheaper extended battery. It's this kind: http://www.amazon.com/Trexcell-3500mah-Extended-Battery-Cover/dp/B004XM9V1KThere are no cases for it, so I decided to make one on SolidWorks.Of course, this part is useful for only people who have an Evo 3D with that specific extended battery. Print out the case, pop your Evo 3D in!