You can find the Ghost Inc Bullet Forward Slide Release Stainless Steel for Glock Gen 1-4 here.

The Ghost Inc Bullet Forward Slide Release for Glock Gen 1-4 has a forward Slide Release design to be faster and easier to use for left-handed shooters. Easy drop-in install does not require modifications to the pistol or gunsmithing.

Color: Stainless Steel
Fits the following Glocks: 17 (3 Pin Only), 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 40 & 41. Does not work on Gen 5.