That’s a UV filter which isn’t really needed in most circumstances.I used to have a protective filter on my kit lens with D90 and that was about 60 pounds or so.
Now I have D750 and 85mm 1.8 and I'm not getting any of that. In those 7 years I had the D90 the lens was practically brand new and the filter was unscratched. Not wasting money ever again. Its just money down the drain.
I don't like these psychological products that count on human desire to be careful when something is expensive. Hence why most stores make money on the insurance itself rather than the product. So bad
So no, not getting into it.
The Lee filters I was mentioning are ND or grad filters. Very useful for landscape photography as is a polariser.