I rang Baileys asking for this a while ago, the lady I spoke to wouldn't give it to me and said I'd be much better off with the number 4 cubes as the Highlight is inferior etc.
I suspect it is quite similar to no 4 but they're not going to tell us that and cannibalise their own business!
If you an confirm it's the mauve bag I'll type the list out for you - I bought them at Robinsons - it starts wheatfeed I think, can't give them to sensitive mare but gelding does well on them