Parallel Pro

The Parallel Pro is an IEEE 1284 parallel printer interface and has a built-in control panel for setup. The optional Buffer Pro add-on expands Parallel Pro's memory with 64K or 256K RAM chips to a 32, 128 or a 256-page buffer. Compatible with II+, IIe, and IIgs.
Source page: https://ae.applearchives.com/all_apple_iis/parallel_pro/
Buffer Pro
Parallel Pro connected to Buffer Pro