The busboard is connected to your power supply and can power up to 20 modules in your system!
The busboard distributes power to up to 20 Eurorack modules. The power supply is either connected via a 16-pin flat ribbon cable or the terminals on the board. There are three LED’s which signal the operational status of each power line.
Dimensions: 154mm x 67.5mm
See https://polykit.rocks/busboard for technical details and assembly.