I got this Basic set and the "Complete Bed Protector Set" that comes with protectors for the mattress, box spring and 2 pillows (for a queen).  This Basic set is just that, and will definitely fit a 10-12" mattress with a topper.  I only had the mattress (approx 11") in the protector at first and there was a ton of room to spare so I added a topper which added another 2-3" and there was still plenty of wiggle room. Doesn't make too much noise, but would have preferred one that fits better.  If you want a snug fit on the mattress I would go with the Complete set (fits a 10"-11" mattress perfectly).