Go to friend’s home to play time I opened the door to see friends card I asked a friend she opened the door and don’t need a key? Friend recently told me her home is just in the door of the function of the passive rfid, into the home only need a credit card is ok, and also special security, is now a lot of home to install the doors with passive rfid, listened to the friend about what I said is a kind of high-tech, another day I go to the mall look at the nice words I have to install a home door, such friends listen to what I said now this door particularly popular, say I know would love.