An excellent product - well engineered and with dual keying was very straightforward to fit in the two different doors in which I required the same key. In terms of price, the cost for dual keying was surprisingly higher than the single key version, and the spare keys are twice the price of the local Robert Dyas key cutter (so don't bother and take the keys which are included to your local key cutter). If I had one technical quibble it is that the template paper sheet which was included was almost impossible to follow (in terms of written instructions) so we just gave up and used the drawing on its own, which was fine. All in all, a great product, albeit a tad pricey.