This is a simple latch handle that can be used to hold doors closed. It's designed for latching onto the back of 2020 extrusion.

The handle has a hex profile that makes sure the inside part of the latch stays aligned with the handle.

The door thickness can be 5-8mm thick. The hole needs to be 3/8". You will need a M5x30 bolt and lock nut to hold the latch together with the handle part. Tighten the two halves until there's slight friction on the door.

You might need to use supports when printing depending on the orientation you use to print the parts. I printed them ‘face down’ on the flat parts and used supports inside the recessed holes. If you printed them laying on their sides, the supports may not be needed.