As I remember, he said it was for the 91 carbine. I got it years ago from a fellow in Buenos Aries who also sold me several rare Argentine bayonets. Mine has Argentine crest stamp and is 56in long. I have one very like yours with the key shaped metal tag on the end. That strap looks much wider than my sling, which measures 47.5' x 0.75'. There's a grainy, blurry picture in Webster's book showing a cavalryman with a carbine hanging from and across his shoulders using a strap both ends of which appear to connect to the sling ring. ADVANCED TECHNOLOGY MSS1500 MAUSER 98 STOCK W/BUILT-IN SCOPE MOUNT SYN MATTE BLK. I've looked high and low to find examples but haven't been successful. argentine model 1891 mauser rifle parts stock frontband w bayonet lug front band. I've never seen a sling like this - or at least one with what I'll call a blade on the end like this. His listing stated that it belongs on a Model 1891 Cavalry Carbine. I recently purchased this very interesting sling from a guy in Buenos Aires.