The OPT 88 (Option 88) expands the BB 44X into an eight channel model. The OPT 88 consists of a printed circuit board with four additional transformers and jacks soldered in place. The OPT 88 installs easily in the blank side of the BB 44X. Assembly is simple: remove the cover, install the board in place, and secure with the supplied mounting screws. No soldering required; all you need are #1 and #2 Phillips screwdrivers.