This is the CZ 75 9mm 19-round magazine, manufactured by Mec-Gar.

This magazine also fits the following CZ pistols: 75B, 85B, SP-01, Shadow, and Shadow 2 pistols. 

Features

• Increased capacity to 19-rounds with aluminum baseplate
• Redesigned tube to improve functionality, heat-treated for strength
• Anti-Friction Coating allows for easy loading and superior anti-corrosion
• High tensile music wire spring
• Polymer follower
• Interlinked internal components