Made from PA6 engineering plastics, Strong and Durable; Easy to use, Efficient work; Allows simultaneous work on multiple walls; 25 feet of nylon wire is included. Material: engineering plastic Opening size: 3.5-4.7 inches（9-12cm） Total weight: 172 g `(6 oz) Packing composition: 2 Clips Line Runners, 25 ft. Nylon wire. Operating Instruction 1. Clamp the Brick Line Runner on the brick, wind the string around the string column and clip it in the string slot; 2. Do the same for the other side and straighten the string; 3. Taking the straight line as a ruler for the bricklaying; 4. Directly moved it to the next layer after bricklaying of each layer.
eBay