I bought a tray and drain. The instructions then told me I needed a specialist cutting tool from the same manufacturer. When I checked your website there was no option to buy one, so I sent an email to say that I was not happy as the items would be useless without it. I was sent an unapologetic email saying that the tool was only a recommendation and not a requirement. As an experienced tradesman who has fit several different tray formers I can tell you the only way to cut a perfect circle at the right size and location is with x ray vision and supermans laser cutting eyes! But don't worry I now have a knife from another supplier who I will be using from now on.