Accessories for 3KF size 5 fourth pole, switchable for NH fuse size 2 and 3 flat connection Comprehensive accessories for increased flexibility. From connecting bridges to auxiliary switches to various drives, fourth poles or contact covers: With a wide range of accessories, the load break switches and transfer switches can be used for different requirements and upgraded at any time. www.siemens.de/schaltgeraete. Siemens offers a comprehensive portfolio of protection, switching, measuring and monitoring devices, distribution systems as well as switches and sockets for safe, efficient electrical infrastructure in buildings and industry.