Elongated Extra-Seitengewehre is one of the Rarest German WW2 Bayonet Frogs. It has elongated back piece and loop and was designed to be worn through the sword slit in the pocket of the tunic if an outside belt was not worn. 8 3/4" total. 

(Please see George T. Wheeler "History of the German Bayonet 1919-1945" pg. 249)

Very nice and strong saddle leather, not dried, no broken stitches.