Sun Hemmi 255D Expert Electrical Engineer slide rule case manual Japan 1970

This complex slide rule was well guarded by its original container, made in Japan by Sun Hemmi. This model is the 255D “electrical communications, aimed at for instance the radio engineer. It comes with the original manual in English, together with the black box I would guesstimate it to be a  late 1970’s model. The slide rules is also shown inside (with several others including a fold out page for longer models). It has scales on both sides and a heavy duty cursor with multiple hairlines. Slide rule and curser are complete and everything is in very good condition with some small signs of use and age only. The cardboard container is complete and signed Hemmi, with the designation 255D on the top, it has a tear in the side of the top part.  It measures ca. 32 cm or 12 1/2 inches. Check out the attached video on how to operate a vintage slide rule!