Went to replace the bulb on the indicator of ZX11 to find the right hand side bulb holder is single filimant (two wire) and the left is dual filimant (three wire). Explains why only the left side runnings lights work...

Are they common? ie on several makes of bikes etc that will fit?

Looks to me like it has been replaced in the past and the previous owner put in a two wire holder, which makes me think it will be hard to find a three wire holder for it....