This Apple MD828LL/A smart cover's microfiber lining provides a reliable safeguard for your device's screen and automatically wakes or puts your iPad mini to sleep. The magnetic alignment ensures a snug, secure fit.
I didn't really understand the difference between the $30 cover and the more expensive one until after I bought it. The cheaper version covers just the front of the ipad. This is okay because shutting off the ipad when not in use is the main reason I bought it. Excellent magnets.