Olivetti Logos 59 calculator, designed by Mario Bellini. It's not a Logos 55; you can see the model name over the "%" button
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/11932978@N00">tomislav medak</a>
CC BY 2.0
<a href="//commons.wikimedia.org/wiki/Flickr" class="mw-redirect" title="Flickr">Flickr</a>: <a rel="nofollow" class="external text" href="https://www.flickr.com/photos/11932978@N00/4958237705">Olivetti Logos 59 designed by Mario Bellini</a>