Got mine from Halfords. Not the best quality in the word, but does the job. From memory, the trolley jack was 2 tonnes ( doesn't say on the jack).
There was a case in our area recently where a couple of lads were working on a car supported just on a jack. One was underneath when the jack let go. The car came down on his head. Moral: use axle stands.
( I believe he survived, by the way).
Ian