My brand new slide rule just arrived!

I don't mean "new to me". I don't mean "new old-stock". No, this is BRAND NEW, from the last company on earth that still manufactures general purpose slide rules, Concise.

This is the Concise No. 300, their top of the line circular slide rule. It has A, B, C, D, K, CI, L, S, T₁, T₂, ST, LL₂ and LL₃ scales. It is 4⅜" (11 cm across), which is very small for a slide rule (my C-Thru is 5" (12.7 cm) long), but the actual scale length is πd, so the outermost scale is equal to a slide rule about 12½" (31.75 cm) long, and the C/D scale is equal to about 9¾" (24.5 cm). My Pickett has scales 10" (25.4 cm) long, so this tiny whiz wheel is comparable to a full-size slipstick.

Despite being made in Japan, this slide rule has markings with Latin characters, allowing it to be used by anyone familiar with a Mannheim-type slide rule regardless of language. The instructions, however, are Japanese-only.