ProMag MKA01: The MKA 01 is a 10-rd box-magazine designed for the Akdal MKA 1919 12-gauge shotgun. The magazine body-cover and follower are constructed of a proprietary DuPont Zytel based polymer to ensure a long service life; with a heat-treated steel tower insert for positive lock-in, and reliable feeding. The spring is made from heat treated Chrome-silicon wire. Fits AR-12 style shotguns such as the Panzer, MKA, Typhoon, Etc. The magazine is designed for the use of 12-gauge, 2.75 inch shells.