A run-safe filter system is provided for confirming installation of a qualified filter element in a housing. Each time the receiving circuit receives any of the packets, the receiving circuit uses the information included in header of the packet to determine whether the packet has been received normally. The at least two partial sections each have a filter material of a different porosity including a first partial section with a great porosity and a second partial section with a small porosity. The rear part of each hook is attached to a sling, and a lock is assigned to it.