One can argue if a UV filter is of any real use in terms of improving photo's by reducing UV light especially in these digital days. However, there is one thing that cannot be denied which, is the actual physical protection the filter gives and that's why all my lenses have one.I recently bought the Sony FE 200-600 lens and given the cost at £1600 thereabouts I was keen to protect the glass from scratches and debris. So, I bought this having previously bought other K&N photography products.K&N make both low end and high end gear. The low end stuff such as the plastic filters is average priced and average quality and the same as much of the other similar on offer. However, where K&N win is the high end of their range. They make stuff that is the equal of the very best but at a price that may not be cheap, but is better value. This is where this UV filter comes in.It's superbly made from optically perfect glass and finely machined bezel. Putting this on made no difference I could see to the sharpness of my photographs and that's ideal.Most of all, it means that I've now got some protection from my grubby fingers and general dirt on my fairly expensive lens.