It is absolutely a reproduction. Note that its body is as flat as a sheet of plywood. None of the actual civil war era Rectangular CSA beltbuckles were flat. Also, it is made of yellow brass, which is incorrect. The shape of the belt-hooks' body is incorrect. And, as Gsxraddict mentioned, no genuine Rectaangular CSA beltbuckles were marked on the back in any way -- no maker's-name, nor date. I mention "date" because fakes are often marked with a civil war year, such as 1861 or 1863, to give the (false) impression that it is really that old.