shower pump for just the hot water on pipe for shower

Hi
My mother in law had a power shower and it was with a single hot water pump and the pump was installed on the feed just before the mixer tap and the cold was from the mains, so not near hot tank, on the supply to the whole house, just by the hot water supply pipe to shower mixer, there was a loft tank for the feed to the back boiler, vented i believe.
So can any body tell me what pump that could have been, as i can only find pumps to fit by the hot water tank, with an flange and a lot of messing about and hers was a simpler one.
Thanks

With all due respect, please repost your question with proper punctuation. I am having a difficult time reading and understanding since everything seems to run together.