So we purchased 12 of these roof drain pads for flat roof applications where TPO is being used directing everything towards the Drain. The original drains would allow certain debris to get through and eventually clog up the drain pipe itself. However, once we added the roof pads around the drain itself, it seems to have eliminated the problem by keeping the small leaves and debris out. We did not attach the pads directly to the roof. We cut an X in the center of the pad and slid it down over top of the drain itself where it clings nicely. so far none have blown off or blown away. We find it is easy to pull the pad off, shake it out, bang the debris out of it and put it back in place. So we think we have solved a problem of the clogging drains at this point in time. So in essence, we recommend this product if you have a similar issue.