The MX30s are the Shimano DX flat pedal classic. They come with both short and long pins and are totally rebuildable. We found the best pin set-up was a mix of the long and short, in an arrangement that enhanced the concave face of the pedals. The pins offer more grip than most too, because of their size.
The only downside to the pins is the fact that they are grub screws. They use a tiny 1mm Allen key that fits in from above, and can easily be damaged when they take a scrape, making getting the Allen key in tough. If they do take a big hit, the pins tend to get torn out.