A sprung modernist bookend, which I believe is known as The Bookworm, from around the 1970s. It's a fab deep bluey grey and is an enamelled metal - typical of the era. Likely by Teleflora, made in England. When uncoiled the self-supporting standalone book holder can hold up to about 18-20cm of books (max). 
Very good for the age and era (if you compare to others available). Some minimal surface marks and a little wear around the edges, but actually very good. The base has a felt coating to protect your desk and some wear the metal base with that, shown. 15.5cm tall x 12.5cm widest at the base. 
Price includes P&P to the UK.