Through terminal block, 281 Series, operating tool This through terminal block (item number 281-654) streamlines wire connections, making them both quick and easy. Conductors can only be connected to this through terminal block if their strip length is between 9 and 10 mm . Whether in industrial or building applications, our rail-mount through terminal blocks are the perfect solution to quickly and securely connect electrical conductors. Depending on the model, you can use them for either typical through-wiring or potential distribution. This product incorporates conductor terminals and utilizes CAGE CLAMP®. 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. Depending on the conductor type, this through terminal block is ideal for conductor cross sections ranging from 0.08 mm² to 4 mm². An operating tool is used to operate this through rail-mount terminal block.