Simple Hidden Child Lock

I've been searching for a simple to install, simple to make child lock but couldn't find anything to my liking, so I decided to make my own. Tolerances are a bit tight but should be fine after wearing them down a little bit.

I've made two versions of the sliding part, one without grooves and one with grooves, I'm using the one without grooves myself at the moment but am planning to change it out for the one with grooves to get a bit more grip.