Do you know what OWT stands for? It stands for “Old Woman’s Tooth”!
I am afraid we cannot use such derogatory language these days.
Properly, it is a router, to finish a recess, or housing.
It makes a chattering noise as you pass it forwards and back across the grain.
I made it over 30 years ago. The body is formed from the foot of a piece of gymnasium equipment. There was another foot, which I also used for an OWT.
The view from beneath shows the iron is a 4-square file. The wedge is rosewood.
This is the other one I made, more like the usual shape.
I prefer to use this to using a machine router for just a small job, no need to bother with PPE, extraction, dust everywhere. Noise.
It does not give a very good finish, so.....