If you're here because you've been the victim of a blown belt, or a blued clutch bell, this strainer is something you really ought to pick up.
This design blocks out large trail debris while allowing fine dust particles to pass through. This is an improvement over stock inlet boots (with filter) for our offroad GY6 vehicles. Dust tends to clog the stock boot inlet. This leads to significantly higher CVT temperatures and premature failures (flattened rollers, blown belts, and clutch issues are the most common).
Even if you try to keep your stock boot clean, it will clog again within another ride or two. Throw that junk in the trash, then install one of these and forget about it.