The Trefoil Draughtsman Compass Refill Leads Twin Pack features high-quality graphite cores designed for technical drawing. Precision-engineered 2mm thick leads incorporate a pre-angled sharp layout point. A specialized H-degree hardness rating ensures crisp, clean lines. Each 25mm long element resists cracking under continuous pressure. The protective plastic container completely prevents loose desk rattling. It fits standard educational and professional geometry drawing compasses seamlessly.