looks like a nutriculture logo top left of the timer (bottom left in your rotated pic)
Here ya go https://www.hydro2grow.co.uk/product-category/accessories/tmu/Bingo!
That's the one, Chron, thank you. Nutriculture TMU.
Sadly, from diggin around online, it seems they've been dicontinued. Shame becaause it was an easy to use, fool proof piece of kit.