Combination plane.

45 Combination plane, used for cutting grooves or rebates into timber.  The lowest part of the plane in the photograph is called the fence, the plane uses a combination of the adjustable fence, adjustable depth and the blade to cut an acurate groove into timber.


The width of the cut is adjusted by loosening the thumb screws and sliding the fence sideways on the two protruding round metal bars. This plane accepts different width blades to cut a narrower or wider groove as need be.
The blade's depth can be adjusted by the screw adjuster near the front of the plane on this image.

The way the fence guide bars are set up in the top photo the plane can be used for cutting a rebate, by moving the two bars to the bottom holes you would be able to cut a grove as in the picture above.