I've only ever used inexpensive filters on my lenses, and only to protect the lens glass. Recently, however, I've stopped using these filters because a UV filter isn't necessary with modern lenses, and inexpensive filters in particular can cause lens flare or ghosting. The K&F Concept Nano-X-PRO UV filter (slim flagship MCUV filter) with 72mm is lavishly packaged in a high-quality manner. The filter also comes with a beautiful felt pouch with leather trim. Mounting it on my 17-50mm Sigma lens is simple and easy, but you always have to be a bit careful not to damage the thread. Inexpensive filters are usually made of aluminum, whereas the K&F filter is made of high-quality brass. A simple comparison with an inexpensive model reveals a huge and decisive difference: everything is reflected in the inexpensive filter. Every light source is reflected in it. This demonstrates the quality and the high-quality coated and anti-reflective glass. For 130 euros (as of November 2022), you get an absolutely high-quality filter for your lens. If you want to protect your lens without compromising image quality, this is the right choice.