A nice duplex trig rule, in the same style as K&E's other duplex rules. This one came in a lovely green leather case. I'm still trying to find out where K&E managed to find all these orange and green cows for their slide rule cases. i'm also trying to get over being a vegetarian with about a gazillion leather cases sitting around his house. Don't tell anyone, ok? i figure i don't need to feel bad about it 'cause they're used, right? i mean, it's someone else's fault the cow gave up its hide for these cases, right? right?