What brand is that filter? I like the Hayes filters. Many years ago I bought 20 in "bulk" without the packaging and with extra screens. I still have a few left. Other filters of similar style are often too large to fit the tight space of a cowled-in "40 size" stunter.
When the screen is intact and properly seated they do a good job of collecting debris. The photos show a filter removed from an ARF Flite Streak near the end of a flying season. I was having to open the needle a few clicks on succeeding flights (a hint the filter needs attention). The debris is mostly wings and other parts from small insects, plant material and spider webs! EWP