Needed these to keep my neighbors dog from continually digging large holes under the fence.  My small dog could easily get through these holes he has made.  Also using them in another location to keep rabbits out of a courtyard areea.  They do the trick!   Can be a little hard to beat in the ground if you have clay soils like we do here. Just use a piece of wood ontop of the metal when beating it in the ground so that you don't bend these barriers