This stainless steel mouse guard is precision milled in Portland, Oregon and made specifically for Warre hives. It measures 6" long by 1" high. The 7 3/8" holes are the ideal size for keeping mice out in the winter, while still allowing bees to come and go. We suggest you get your mouse guards on in the fall just before the temperatures drop too low for the bees to break cluster and protect the hive from mice. Be sure to clear out the dead bees behind the mouse guard frequently during the winter time.