This is a drilling template, it's not a guide in the traditional sense, as it has no metal bush to guide the bit, but with care it will certainly last long enough to drill four holes in a table top or in the end of some Ikea Lack legs.
It comes in three sizes 6, 8, and 10mm respectively and each of the drilling “guides” is a gentle fit into the corner template, placing the hole exactly 25mm from each side.
Print in two parts as shown, no supports needed. Mine is in PLA, but anything will do.
To maximise accuracy, when drilling larger diameters I recommend starting with the 6mm one and drilling successively larger holes.
The author marked this model as their own original creation.