12/13/17 - This is an original WW2 production MP.38/40 magazine. The magazine is a rare variation "slab side" , meaning there are no ribbed grooves on either side of the magazine. The spine of the magazine is "fxo" maker stamped with two eagle/37 proofs and a '41 date stamp. Guaranteed original and authentic. The spring is strong and fully functional. There is some minor bluing loss, but overall the condition is excellent.