Erica Synths Drum Sequencer has connectors for internal Trigger and Accent connections to Erica synths Drum modules. The connections are made via six wire ribbon cables with 2x3 connectors (similar to Eurorack PSU connectors), and you can save some patch cables if you have a lot of Erica Synths Drum modules. Internal connections will work only with Erica Synths modules and no other manufacturer module will support this functionality. If you have Erica Synths Drum Sequencer and other Erica Synths Drum modules and want to use internal connections, select “Hi-Hats D with internal connectors” option. If you do not want to use internal connections, select cheaper “Hi-Hats D without internal connectors” option.