An OBE (on-board equipment) is an electronic unit received from your Service Provider which shall be mounted according to the mounting regulations also provided by your Service Provider. When the OBE is registered at the toll station or tolling gantry the toll fee will be charged according to your contract with your Service Provider.
An overview of countries and toll stations included in EasyGo can be found via the map or here.
In Norway, Denmark and Sweden all approved EasyGo OBEs can be used. If you will be travelling to Austria or Slovenia, you will need an EasyGo+ OBE. The overview of Service Providers shows which Service Providers offer EasyGo+ OBEs.