Ordered the 'Universal 15.6" inch Anti-Glare Laptop/ Notebook Screen Protector Film for Dell Lenovo ASUS HP Acer (345 x 194mm)' by WengTech for an Asus 15.6" K55A laptop which has a very glossy screen.
I'm happy to say that this protector fits the Asus K55A 15.6" screen perfectly (the height of the protector is a little smaller than the screen - about half a millimetre clearance at the top and bottom but it's barely noticeable).
After applying the protector, the screen is now matte and much better on the eye (no more eyestrain or constant light reflections).
It's only for use indoors so I can't comment about outdoor use.
The screen protector itself is a piece of flexible plastic with a flimsy film cover on either side which have numbered tabs to tell you which film to remove first (Number one is removed first) - similar to many protectors for cameras and touch devices.
If you've never applied a protector before, there are a few things that will make it easier like keeping some sticky tape in a loop (sticky side out), handy, to make removing dirt/fibres from the protector/screen easier. This is after you've used the cloth and have found trapped particles under the protector as you're applying it.
Also, try to peel off the first film as you apply the protector, 'rolling' the protector on using the credit card sized piece of plastic supplied - you can also use this plastic to squeeze out any air bubbles around the edges after application so try to make sure there are no bubbles around the middle (pull the plastic protector back and use the little plastic card to flatten the area and squeeze the bubble out). Depending on the bubble sizes, some that are trapped may dissipate over a few days.
I've used other protector brands on other laptops and devices. I find this one does the job.
It can be frustrating applying these kind of protectors. I've thrown many away but after I watched and read about someone else's 'how-to', it got a lot easier.
I bought this purely as a matte screen cover for a glossy-screened laptop and it does exactly that. So based on my experience, I would recommend it and buy it again if needed.