These Great Western Railway Spagnoletti single line crossing indicators are very rare, in 30 years of trading Ive only had 3. This combined flag indicator and bell instrument would has been in a small crossing keepers ground lever frame box or small station office where a hand operated level crossing was in use on a single line. The signalmen either end of the single line use the key token instruments for authorising trains on to the single line. There bell signal were repeated on this instrument and up train or down train on line would be indicated in the small aperture on the instrument face. This instrument is in exceptional conditional being well over 100 years old, everything tested and working as it should.