QUOTE(Ashrafx @ Feb 19 2023, 07:36 AM)
i dont really know. which one is better for watch?

tempered glass being flat won't really cover the whole curved screen, and there is always a few edges with non-activated or non sticking adhesive hence you get the edges with bubble or air gap. very ugly.
with phones you can add some oil underneath and it patches like a charm but with a watch i think it wont work as you may swim and bathe and wash hands with your watch.
when it is used, a glass will always be the best protection for your screen. i have used this method for my last 10 years of gorilla glass phone experience and not a single one of my phone has a scratch on it.
but the problems with a dual curved display like the apple watch really prevents great use of tempered glass.
so you are left with the flexible screen protectors. i have one on my watch and with patience and time you can stick it very nicely. but it will not stop drop and crack damage. you need a case with higher lip or edges to absorb the contact and impact.
the screen protectors are called hydrogel or tpu or whatever name, they usually are less than rm2 each.