Approx. 1/2mm thick. Nice and thin and stretchy too. Well suited for this purpose :-) Anyone expecting a "thick" cloth will be disappointed, because these cloths are thin. But that's not a disadvantage, but an advantage, because it makes it easy to reach the edge of your glasses or behind your nose bridge to clean. 

Please check sub-table 2 for the operators corresponding to different countries, please update the operation according to your site. For example Germany is: T-Mobile, Vodafone, E-Plus E-+ Mobilfunk 

1.I’m sure it’s glass - when I clean mine with isopropyl alcohol they make that ‘squeaky’ noise you get with glass rather than plastic, and they’re more resistant to scratches than most plastics are. According to manufacturer website K & F use German optical quality glass so I’m sure they would have been called out for that a while ago if it wasn’t true 2.I drop one last year and it broke like glass ..I’ve found them easy to clean and well made. 3.Looks and sounds like glass to me 4.HD optical glass 5.As far as I can tell it is glass. Excellent optical qualities 

Hello, we don't sell screen protectors, this watch's screen size is 1.69 inch, you can find them in the market according to this size. ^-^ 

You could try this tip. Hope it helps. Pan&tilt operation: Press the “pan/tilt” button on the upper right corner (A direction icon will appear in the middle of the screen when you press the “pan/tilt” button) →use the sound and brightness buttons to move the lens(The specific operation is shown in the video).