Please don't buy one from the above link, I bought two that both failed. The company are a nightmare to deal with and did not get my £40 back. Save your money and get a genuine one please.
Buy cheap, buy twice! My original lasted 10 years, my original replacement @ £80 will also last 10 years, eBay specials are made from inferior materials, but if you like to pull your door to pieces every 1 or 2 years that's up to you, I have better things to be getting on with.......