i know, i know. i haven't the foggiest idea what happened in that second picture. but it's kinda cute all scrunched up like that, isn't it?
Basically a bigger version of the 4098A (i totally don't get K&E model numbers at all) with a nicer cursor. The design is otherwise pretty much identical. Still, like the other plastic K&E rules, this is a pretty nice little slide rule.