This is the Steyr Mannlicher M 5 round factory rotary magazine in 9.3x64 for rifles with the new style dual side lock magazine.
The rotary magazine design is flush fit to the stock and is made of a tough polymer with a clear viewing plate at the rear.
Brand: Steyr
Weight: 50 Grams
Calibre: 9.3x64
Capacity: 5
Model fit: M
Material: Polymer
Colour: Black
Item Nr.: 102-2700050505