Vauxhall / Opel Astra Mk3 (F) 2.0 (91 > 94). These award winning Black Diamond Brake Discs are made to the highest standards using computer aided design technology and computerised production. The Black Diamond G6 Range of Discs is specifically designed with 6 Curved Grooves giving you a fantastic braking response and greater friction, but at a lower price than the 12 Grooved version.