Alongside its first touchscreen MacBook Pro, Apple on Tuesday introduced the Magic Armrest, a $199 machined-aluminum support that holds the user's forearm level with the display, which the company called "the most natural way to touch a Mac."

"Without the Magic Armrest, after an extended period of time, your arm wants to fall off," said accessories vice president Lauren Choi quoting the late founder Steve Jobs. "We think our customers deserve better than that."

The armrest comes in Silver and Space Black and is sold separately. A Magic Armrest Pro, at $349, supports both arms and adjusts in 0.5-millimeter increments using a crown borrowed from Apple Watch. AppleCare+ for the Magic Armrest costs $39 a year and does not cover the arm.

Apple said its testers used the touchscreen for 11 times longer with the armrest than without it, and that the company has filed 64 patents on the angle of the elbow.

Early reviewers praised the fit and finish but noted that the armrest charges through a USB-C port on its underside, meaning the arm must be removed while it charges.

Preorders begin Friday, with shipping estimates of four to six weeks, which Apple recommends customers spend holding their arms up to build tolerance.