Captain Fields` Pattern - Bar Parallel Rule 500mmDivided with protractor markings (double reading) and compass pointsManufactured from high quality 6mm acrylic. Bevelled on all four edges with solid brass links. All other metallic parts are manufactured from non-corrosive materials. Rubber pads are fitted to the underside to prevent slipping.Sizes Available:400mm500mm600mm For more information or to enquire about Blundell Harling products, please email maritime@stanfords.co.uk .