The StewMac Precision Straightedges are the gold standard for guitar neck and fret evaluation, ensuring accuracy for truss rod adjustments, fret leveling, and neck relief checks. Designed for professional luthiers and repair technicians, these straightedges provide unparalleled precision and durability.Crafted from ultra-high-grade stainless steel, each straightedge features a satin finish for improved visibility and the ability to mark measurements with a pencil. The narrow beveled edge allows for precise gap inspection, making it easy to detect uneven frets and neck imperfections. Guaranteed to ±.0015" per foot accuracy, these tools are trusted for professional guitar setups.Available in four sizes to accommodate different instruments and applications:#3849 - 12" x 1.5" x 0.079" (304mm x 38.1mm x 2mm) – Ideal for mandolins, ukuleles, and short-scale instruments.#3850 - 18" x 1.5" x 0.079" (457mm x 38.1mm x 2mm) – Great for guitars and part of the Basic Setup Kit.#3799 - 24" x 1.6" x 0.118" (609mm x 40.6mm x 3mm) – Designed for acoustic and electric guitars, compatible with the Neck Set Gauge.#3800 - 36" x 1.6" x 0.118" (914mm x 40.6mm x 3mm) – Perfect for bass guitars and long-scale instruments.Each straightedge undergoes a rigorous 13-step manufacturing process and is individually inspected to ensure maximum precision. Unlike aluminum alternatives, these tools resist bending and denting, ensuring reliable performance for years to come.Perfect for luthiers, DIY musicians, and even precision woodworking, the StewMac Precision Straightedges deliver professional results in every setup.