Berghaus somethings. Sorry, not very helpful. Mine have lasted for ages and cost £30. Full length, and cheap enough to not really worry too much about. Mine have a couple of repairs, but due to my fault, not the trousers.
Possibly these ones but I'm not sure what I have.
http://www.gooutdoors.co.uk/berghaus-deluge-mens-waterproof-overtrousers-p1...
On a related note, what is the point of the mesh liner inside some cheaper waterproof coats/trousers?