This is the 10 round factory 12 gauge magazine for the Derya MK-12 shotgun.
Also fits the Derya MK-10 and should fit common Turkish AR style box feed guns e.g. Typhoon, Kral, Makarov, Barak, MKA and others using the stick out rear last round lever design.
Manufactured from heavy duty steel with a black coated finish the magazine is fully strippable for cleaning if you remove the polymer baseplate.
Also available in 5 and 19 rounds sizes.