2x Sun Hemmi 281 + 280 Ahrend full set slide rule 1970 Japan

An interesting combo of 2 slide rule by Sun Hemmi from Japan. Model 281 and the 280 for the Dutch Ahrend Group (Office Equipment) in The Netherlands. The 280 is the same as the 281 but has some additional scales on the back of the slider. Both comes in the same original Hemmi & Ahrend signed plastic container but with different sticker. Fun thing is that both are covered in the same manual if which 1 is included. Both pieces are in great condition with hardly any signs of use and age. They measures ca. 33 cm or ca. 13 inches. Check the attached video on how to work your vintage man tool : slide rule operation instructions!