The PowerBook Duo was a line of small subnotebook

Subnotebook

A subnotebook is a class of laptop computers that are smaller and lighter than a typical laptop....

s manufactured and sold by Apple Computer

Apple Computer

Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

 from 1992 until 1997 as a more compact companion to the PowerBook

PowerBook

The PowerBook was a line of Macintosh laptop computers that was designed, manufactured and sold by Apple Computer, Inc. from 1991 to 2006. During its lifetime, the PowerBook went through several major revisions and redesigns, often being the first to incorporate features that would later become...

 line. Improving upon the PowerBook 100

PowerBook 100

The PowerBook 100 was a portable subnotebook personal computer manufactured by Apple Computer and introduced on October 21, 1991 at the COMDEX computer expo in Las Vegas, Nevada. Priced at US$2,300, the PowerBook 100 was the low-end model of the first three simultaneously-released...

's portability (its immediate predecessor and Apple's third smallest laptop), the Duo came in seven different models. They were the Duo 210, 230, 250, 270c, 280, 280c, and 2300c, with the 210 and 230 being the earliest, and 2300c being the final incarnation before the entire line was dropped in early 1997.

Weighing in at a mere 4.1 pounds and slightly smaller at 10.9 by 8.5 in (276.9 by 215.9 mm) than a sheet of paper, only 1.4" thick, it was the lightest and smallest of all of Apple's PowerBook

PowerBook

The PowerBook was a line of Macintosh laptop computers that was designed, manufactured and sold by Apple Computer, Inc. from 1991 to 2006. During its lifetime, the PowerBook went through several major revisions and redesigns, often being the first to incorporate features that would later become...

s of its time.