Generally, I rarely use more than one ballpoint color... so, it's really fine to have just 2 writing types -- ballpoint and pencil.
This is made by Mitsubishi. I'm impressed with the quality of construction. Very similar to Pilot... although I'd give a slight edge to Pilot. But Mitsubishi isn't well known for writing instruments outside of Japan, thus their vintage resale prices are quite a bit lower. This all steel multi-pen is fairly light weight, just heavy enough to feel like it's reasonably substantial. This is a twist mechanism -- right for the ballpoint, left for the pencil. It's not particularly smooth, but it does notch into place well. It acts like a vanishing point, as there's no pesky tip protruding that would poke a hole in your pocket.
But what's so great about it is the form factor. It's just thick enough for comfort. And the black stripes provide ample grip. Really a "flying under the radar" value on this one.