Keith, similar to, but yours is a different colour, has a different pitch and, is much thicker walled, also only appears to have two ribs. I actually think it's more attractive. Lots of companies made tumbler vases with optic ribs - Whitefriars, Tiffin in the US.
Nigel, thanks for the confirmation. I thought it was fine, but wanted an expert to confirm it.
As to why the thread is in Glass, it's GMB policy for any ID queries to be moved to the Glass section before moving to the more specific boards after identification.
Mod: - added later: Just to clarify, Keith had started the thread in the Cafe, hence the move to Glass.