Durable electro-plated black finish for exceptional corrosion resistance - Compatible with ZF-5 ZF-5P ZF-5K MP5 SP5 HK94 MP5K SP5K SP89 MP5SD and other 9mm roller-delayed blowback firearms - All steel construction - Round count indicator holes on the rear of the magazine - Stainless steel follower - Reinforced feed lips - High-tensile compression spring