Through terminal block, 880 Series, operating tool This through terminal block (item number 880-904) is designed for simple and secure connections. Strip lengths must be between 8 and 9 mm when connecting conductors to this through terminal block. Whether for use in industry or building installations, our rail-mount through terminal blocks allow you to quickly and securely connect electrical conductors. They’re perfect for either classic through-wiring or distributing potential, depending on the variant. Featuring conductor terminals along with CAGE CLAMP®, this product outperforms the competition. Our reliable and maintenance-free CAGE CLAMP® connection makes it easy to connect all conductor types without having to prepare the conductor. For example, you don't need to crimp ferrules. This through terminal block is suitable for conductor cross sections ranging from 0.08 mm² to 4 mm². This through rail-mount terminal block is operated with an operating tool.