When you're starting out in Olympic lifting, you can't be expected to lift the heavy weights off the floor on day one! Its also dangerous to go too heavy too early. Olympic lifting is all about getting the technique right, then slowly increasing the weight. So, lighter weight plates that can take the knocks and are a full 450mm diameter are important in developing good form. These plates are 42mm thick with 51mm diameter centres.
Manufactured from synthetic composite, Cyberfit technique plates are able to perform in commercial lifting gyms where people are going to drop the bar on occasion. They resist bending and keep their shape, giving them a longer life than equivalent rubber plates.