Mountain Dulcimer, three string. Tuning is DDG
This appears to be a home or kit built dulcimer. It is a nice standard dulcimer size, hour glass shape, F sound holes, with nice tone.
It has geared tuners. The woods are solid Alaskan yellow cedar top and oak ply body.
If you are looking for a chance to try the mountain dulcimer without spending much, this is a great way to go!