It has been made under licence from the BBC by several makers over time and numerous copies exist it can be a DIY job and I've made a few of them over the years for friends and they are still in dally use!.
Not that loud and not great for loud bass heavy stuff but for a lot of classical and voice reproduction it will stand up well against the QUAD ESL-63 and the like.
It will be interesting to see what that pair go for, usual selling price is around a grand! .. or more!...