Not a bad piece of kit, took about an hour to install then it took two hours of head scratching trying to find out why it wont work! Waded through the instruction book several times but no joy. Eventually phoned the help line where they informed me it wont work without the cover on. Doh! It has a magnetic switch to sense the cover is in place. On fitting the cover i found there is a label telling the installer this but it is hidden and not obvious hence my overseeing this but it would help if this was flagged up in the instruction book. Otherwise very happy with the product.