RC610 Horizontal Markers The RC610 series of terminal markers for use with the ABB SNA range of DIN rail terminal blocks. These clip in terminal markers allow for quick identification of DIN rail terminals, and are available with a wide range of identification options. The RC610 series is recommended for use with 6mm spacing spring terminal connections. SNA Series Accessories ABB terminal markers, suitable for use with the ABB SNA range of DIN rail terminal blocks.