Vintage Hewlett Packard HP-25 Calculator in Case with power supply . | eBay
CIBSE on Twitter: "Find out about our new digital tool - the CIBSE Embodied Carbon Calculator, in our upcoming #GrowYourKnowledge webinar, live this Thursday from 11:00 (BST): https://t.co/IfAgOUpm1I https://t.co/oFgeWCEnCp" / Twitter