Rolls-Royce Bristol Siddeley Olympus Mk.301 jet engine serial number 650179 in the Aviation Museum of Central Finland. This example was the number four engine (right outermost engine) of Avro Vulcan XM612.
<a href="//commons.wikimedia.org/wiki/User:MKFI" title="User:MKFI">MKFI</a>
<span class="int-own-work" lang="en">Own work</span>