An Apple white paper summarized the Apple Personal Modem 300/1200 features:
“The Apple Personal Modem is a compact, 1200/300-baud modem that provides a cost-effective data communications solution for any Apple personal computer system. With the modem and appropriate software, your Macintosh or Apple II computer can communicate with other personal computers, minicomputers, and mainframes to send reports and graphs between offices, access data bases and commercial information services, find out the latest stock prices, or shop and bank from your own home.”
At the time of its release, the modem worked with several types of Macintosh and other Apple computers: Macintosh (128K, 512K, 512K Enhanced), Macintosh Plus, Macintosh SE, Macintosh II, Apple II GS, Apple IIe, Apple III, Macintosh XL, and Lisa. The modem did not ship with cables because several different interfaces were in use at the time: Apple System/Peripheral-8 Cable (Macintosh Plus, Macintosh SE, Macintosh II, or Apple IlGS); Macintosh Peripheral-8 Cable (Macintosh 128K, 512K, 512K Enhanced); Apple IIe Peripheral-8 Cable; Apple Ile Modem-8 Cable (Apple Ile, Apple II Plus, Apple II, Apple III, Macintosh XL, Lisa); and other computers with an RS-232 port.
This modem in my collection appears to have never been used, and all original paperwork, manuals, and packaging was included in the box. Thus, I was able to provide an “unboxing” of a 1987 product. Note that the internal packaging is mostly styrofoam and the Apple logo is embossed in two different locations in the styrofoam.
Source: Apple (PDF)