Apple Watch screen protection: tempered glass and films

An Apple Watch screen mostly takes knocks from door frames. Two answers here: tempered glass on its own, hard enough to take the impact instead of the display, or a case with built-in glass, full-cover or metal frame, which also covers the sides. Flexible films complete the range. The touchscreen responds normally. Cases from 38 to 49 mm, Series, SE and Ultra, to be specified on the product page.