Check the listing for details. 15" Brushed Aluminum Arms Parallel Rule (Weems & Plath 141). Condition: New. Listed at 39.90 USD. Of all our traditional parallel rulers, the 15-inch (38.1cm) Brushed Aluminum Arm Parallel Rule is a best-seller. This sturdy acrylic parallel rule includes a protractor scale, is easy to use, and is a necessary tool for every seagoing navigator. The two straight-edged rulers are connected to maintain the same angle. By walking the rules across the chart and securely holding down the non-moving ruler, you can effectively plot a course. 15-inches (38.1cm) long Brushed aluminum arms Polished aluminum handle Milled acrylic with beveled edges Includes protractor scale Protective plastic sleeve Lifetime warranty Length: 15 in (38.1 cm) Width: 2.5 in (6.35 cm) Height: 0.5 in (1.27 cm) Weight: 0.4 lb (1.27 cm) UPC Code: 721002001412 HTS Code: 9017.80.0000