The non-vector sibling to the N1725, and it shares all the nice design characteristics of that one. Dietzgen sure made nice rules. Their cases were pretty nice, too, with fancy latches for the flap. On the other hand, neither this nor the 1725 seems to quite fit in its case; they're terribly hard to remove. i mean, it's not a big deal, but what if there's some kind of emergency and you need to get to your slide rule fast?