Alvin® Paral-Liner® 48" Mobile Parallel Straightedge An excellent addition to your drafting table. The Alvin 1101-48 Parallel Straight Edge 48In is a mobile straightedge with plexiglass edging to prevent the device from creating ink smudges and protect finished copy. Frictionless operation, as it glides across the table, makes sure precision marks appear exactly where intended. With black satin finish and boasts rigid phenolic construction, it is durable and attractive. Mounts to your existing draft table with just a few pieces of hardware. Mounting instructions and hardware are included. 4 ft. length ensures lines are accurately recorded across the width of the surface. Never guess by using a generic straightedge. Uses steel ball bearing pulleys to provide seamless movement. Nylon rollers retract, allowing the blade to secure for accurate drawing. Never question the precision of your lines again.