The CN173 is available in Chassis Mounting (CN173) or in Panel Mounting (CN173a). The unit has 8 separate dual line switching, it can switch both the Live (Positive) and Neutral (Negative) at the same time giving a fully isolated section after the switch. As each switch has its own Input and Output, this means you can switch different types of voltage on the same board.
Channel 1 could be 16v AC for Points,
Channel 2 could be 3v for LED Lighting circuits,
Channel 3 could be 12v from speed control to switch Programming track, or just isolate a section of track.
The List goes on.
The LED is colour coded
It shows Green if DC voltage and polarity are correct.
It shows Red if DC voltage polarity is incorrect.
It shows Orange if using DCC voltage
 
Board size is 107 x 48mm
Voltage Range: 2v to 48v AC or DC
Current Rating: 3 Amps per Channel