The Hexpander MIDI interface is for Guitar or Bass and Includes:

BD-0440-00 Hexpander MIDI interface
BD-0540-00 13-pin Output Jack
BD-0515-00 13-pin Mounting Plate
BD-0512-00 Interface Wiring Harness
BD-0511-00 Extension Wiring Harness

The Hexpander does not require a battery because it draws power from the MIDI converter through the 13-pin connector.

You will also need to order ghost Saddle Pickups or a ghost-loaded Bridge Assembly to complete your ghost system. Pickups are different for every type of guitar or bass bridge, so they are always ordered separately from the ghost modules.

You may want to add to your installation:

PE-0111-00 QuickSwitch for MIDI/both/guitar
PE-0180-00 Program Up/Down switch
PE-0181-00 Hexpander MIDI Volume Pot

If you want all three of these options with your Hexpander, it's better value to order the Hexpander MIDI interface Kit.