Guardian entrance reducer

Has anyone used the guardian entrance reducer to combat hive beetles? If so how did you attach it? Was it affective

I was able to install the guardian by attaching it to a small piece of plywood cut in the same shape as the FH2 entrance reducer. Seems to be working nicely so far. Attaching a pic.

Do these reducers stop European wasps from entering the hive? I have a lot around my hives and see some enter, but I also see bees drag them out again.

Any entrance reducer would help with wasps…but. They could still enter. The smaller entrance simply
Makes it easier for the bees to guard against intruders. However the real strength of the guardian entrance is against SHB.