Alvin® Paral-Liner® 36" Mobile Parallel Straightedge This mobile straightedge is the perfect tool for drawing or drafting. Floating action nylon rollers provide smooth and frictionless movement for easy repositioning along your project. The rollers retract at a touch, securing the blade firmly so you can draw along the straightedge without it moving. The Alvin Paral-Liner also has elevated acrylic edges so you will not smudge your pencil or ink lines as you move it around the page. All the mechanisms on this straightedge are fine tuned on steel ball-bearing pulleys for smooth and easy operation. This straight edge is 36 inches long, and is constructed of rigid phenolic resin with an attractive black satin finish. Comes with easy to follow installation instructions and all necessary mounting hardware. Alvin has been one of the leading suppliers of quality drafting and drawing supplies since 1950, and strives to meet their customer's needs by expanding their range of fine art, hobby and craft supplies, drawing room furniture, and exclusively-designed products.