IBM Selectric Typewriter - History, Models, and Related Machines - Selectric II

The Selectric remained unchanged until 1971 when the Selectric II was introduced. The original design was thereafter referred to as the Selectric I. These machines used the same 88-character typing elements. However they differed from each other in many respects:

• The Selectric II was available with a Dual Pitch option to allow it to be switched (with a lever at the top left of the "carriage") between 10 and 12 characters per inch, whereas the Selectric I had one fixed "pitch."
• The Selectric II had a lever (at the top left of the "carriage") that allowed characters to be shifted up to a half space to the left (for centering text, or for inserting a word one character longer or shorter in place of a deleted mistake), whereas the Selectric I did not. This option was available only on dual pitch models.
• Stylistically, the Selectric II was squarer at the corners, whereas the Selectric I was rounder.