I actually bought this kiln from elsewhere before Cookson added it to their stock but I thought I would leave a review here as it maybe helpful to others contemplating buying it.I have found the Pometheus 7 Kiln to be very reliable from the get go as far as being able to follow the firing times given on the packaging of the bronze and copper I have used. I did do as they suggested and do some trials before I fired pieces I had spent a lot of time on and all were fine. I have yet to use it on silver clay but I think that will be easier as it seems carbon is not necessarily required. They say they must be placed on a fire proof work surface, which I didn't have and I found the cheapest way to achieve this was to buy a piece of steel sheet from a well know auction site, you can get it cut to size etc. It so far doesn't seem to have used masses of electricity, power costs being what they are today these things have to be thought about. I bought this one rather than any of the others out there because the firing chamber is a good size but if you don't intend to do a lot the smaller version may well be enough