Question: what is the difference between the series 3 and 5?
Answer: The Series 5 has a slightly bigger screen that occupies more space on the watch's face compared to the Series 3, and comes in new size options. While the Series 5 is available in 40mm and 44mm case options, the Series 3 comes in 38mm and 42mm sizes. ... The Series 3 lacks this capability as well.