This is a replacement sliding latch commonly used in aluminum extrusion window frames found in RV's and other light duty applications such as screens. I made this slightly (0.1-0.2mm) large for my application as the consistency in parts in these applications is nonexistent. I strongly recommend PETG or ABS as these parts are frequently exposed to light, temp changes, and physical stress.

The first file is a thicker ( in the direction facing you looking at the front of the frame) version that seems to fit better in some applications, the second file is the thinner version.