It's a valve DI made by Ridge Farm recording studio, going by the wonderful name of the 'Gas Cooker'.
There were two versions, the one in the picture is the older, light blue version, and there was a second one in a darker blue. I don't think the studio exists any more, but there's still info online about the DI. They are rather pricey now it seems, but it is a phenomenally good DI/valve preamp.
I had one for many years, sold it here if memory serves me well.