Hobbies Glass Fibre Brush (4mm) The abrasive glass fibre pencil is ideal for accurate and rapid cleaning, de-rusting and surface preparation on a variety of materials. The propelling pencil action exposes more or less of the glass fibres. The shorter the fibres showing, the more abrasive the action. Hobbies Glass Fibre Refills for Propellant Pencil (4mm) x 10 Ideal for working with metal, wood, plastics and a host of other materials. For de-rusting, deburring & cleaning. Glass fibre refills are perfect for precise and effective material removal. These excellent tools are great for cleaning & de-rusting, deburring, polishing & burnishing, surface preparation, erasing & removing. IMPORTANT: Do NOT Touch Glass Fibre Tip Hobbies Precision Modelling Tools The Hobbies Precision Modelling Tool Collection is a comprehensive and essential range of useful, often hard to find precision tools and accessories. This range tools & accessories covers many applications where detail, precision and close up control are needed, such as: model making, model boat building, model aircraft construction, dolls house, general hobby & craft, electronics & light engineering, renovation & restoration, jewellery making, as well as smaller DIY and household repairs.