At only 3.7 inches by 2.20 inches, The Light Phone II ($350) is barely larger than a credit card. The screen is a black and white e-ink display, unique to smartphones but similar to the display of a kindle. With light usage, the battery can last 1-3 days without charging.
The device is also lighter in weight than some popular smartphones at 2.75 ounces (78 grams). To put that in perspective, that's smaller than both the Iphone 11 (6.84 ounces) and the Samsung Galaxy s10 (5.5 ounces).