It's been some years since I used C&G. They replaced 3 windows for us. Chris (the C in C&G) is a professional and un-pushy salesman. He offered a ten year guarantee and, when asked, some local references. They don't manufacture their own windows but have them made by third party and fit them -they are quite open about that and in fact there can't be that many window manufacturers in the UK really. Within a few years two of the window mechanisms developed faults and an engineer came out promptly and fixed them. One of the windows took over an hour but was and still is perfect once fixed. Good quality service and follow up.