This is a set of four items. They are products that cost about 40,000 yen in total on Amazon. They were functioning normally until they were removed recently. They were installed on a RAV4, but I think they can be installed on other car models as well. These are used items in normal condition, so please refrain from purchasing if you are sensitive to such things. * DEI Viper 3400v car security system * DEI Field Sensor 508D * DEI High Sensitivity Shock Sensor 504D * Directed Electronics 629L Blue LED Scanner