They are actually pretty nice as an inexpensive alternative to the high end housings. They definitely the $300 ziploc bags you can buy. They fit just about any consumer video camera and it works by a tripod screw on the bottom of the housing that screw into the camera. You can set it up so you can control your record and stop, but thats it. Limited but good for a bare bones housing.
theres a list of cameras that it can operate with on the site epiccam.com, and u can operate the recording by pushing the back of the black end cap. if your camera has an lcd screen that can be turned and backed into the camera then you can have a great view of what your filming.