Well guys I returned home from work and there on the table was my Canon ERC-E4M.
It comes packaged in it's own little canon grey pouch, and packs up quite small which is handy for fitting in an already full camera bag

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The material seems quite thin compared to that of my Think Tank Hydrophobia, but nevertheless its waterproof so thats the main thing i guess. The cover is essentially a large piece of waterproof fabric with a handy plastic clear window for seeing the controls on the back of your camera.
The cover comes fitted with an eyecup to fit 1D series camera though a spare one is provided for the smaller cams (5D, 500D etc). The cover has quite a few velcro straps which are used to fasten the cover tightly round the lens hood of (my 300 2.8IS). Must say it fits perfectly and there's plenty of room to get your hands in underneath the cover when operating your cam. Also the cover works well when rotating the lens on the tripod collar so no problems there.
All in all it looks pretty good, obviously I can only really test it when out in the rain, though I'm confident it'll do the job.
i ordered from Ebay from a Hong Kong seller for £48 and it took a week to get here so thumbs up for the service.