Reptilia's BlackHole Magwell delivers a faster, more intuitive reloading solution! This magwell is compatible with the 9mm and .40 S&W models of Glock 19 Gen 3, Glock 19 Gen 4 (with and without backstraps), Glock 23 Gen 3, and the Glock 23 Gen 4 (with and without backstraps). Once installed, the BlackHole helps facilitate more efficient reloads without adding unnecessary bulk to your carry or duty sidearm. In addition, the BlackHole utilizes a unique rear spacer to ensure seamless fit and compatibility with both Gen 3 & Gen 4 frames.