This is a CZ® Scorpion EVO 3 S1 10-round windowed magazine in 9mm.
Combining lightweight polymer construction with reliable steel spring internals, these small 10-round magazines offer a practical, low-profile alternative to higher-capacity magazines. Originally released just a few years ago, the CZ Scorpion EVO 3 is a pistol-caliber carbine (PCC) that quickly took America by storm thanks to its futuristic aesthetic, superior performance, flawless reliability, and affordable price point.