This is a combination pen and pencil. It appears to be anodized aluminum with a flat finish. The standard pen colors are red and black. The pencil is 0.5mm. To select the pen or pencil the pencil must be held on it's side as in the picture.
Gravity then locates the section to be advanced.
The plunger at the top can then be pushed to advance the selection. The button near the clip is pushed to retract the selection, which is spring loaded. The selection is engraved at the left center. The front section is round and can be unscrewed to change refills or leads. The top can be pulled off to access a small eraser.