Through terminal block, 280 Series, gray Our through terminal block (item number 280-633) is designed for seamless electrical installations. 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 make it easy 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 connector is highly versatile. Our CAGE CLAMP® connection offers a reliable and maintenance-free way to connect all types of conductors. You do not need to prepare the conductor in any way, such as crimping ferrules. Depending on the type of conductor, this through terminal block is ideal for conductor cross sections ranging from 0.08 mm² to 2.5 mm². An operating tool is used to operate this through rail-mount terminal block.