I believe it is. Ought to be six inches long, though - it's a standard size.
Also, I got a loaner sitting right here that looks just like it. :D
http://straightrazorpalace.com/membe...5019-4inch.jpg
Coincidentally, I had this pic saved with the 4-inch line superimposed in blue to show someone what a 1x4" would look like.
Yours does seem a little lighter than this one (that's a dark picture of the one I have, though), but since this was such a common size for M. Thuringians, I bet that's one.
(Plus, if I'm not mistaken, someone unloaded a bunch of these on B&B recently.)