ProMag SKS-A4: This is a magazine designed for SKS rifles and carbines. The springs are made from heat-treated chrome-silicon wire for increased reliability and smooth feeding. Made in the U.S.A. NOTICE: Due to the variability in mag-well dimensions in the wide variety of manufacturers of the SKS rifles and carbines, and in how they have been converted for the use of detachable magazines; this magazine may require hand-fitting, or may not be suitable for your individual firearm.