About This Self-Centering Accuracy: The parallelogram linkage automatically centers the marking bars on any board thickness, so you get reliable alignment for mortise and tenon joints without measuring Interchangeable Inch Bars: Includes 4 stainless steel bars in essential imperial sizes—1/4", 3/8", 7/16", and 1/2"—so you can quickly match your chisel or router bit for precise joinery layout Knife & Pencil Ready: Polished stainless steel bars work with both a marking knife and a pencil. Score clean knife lines ready for chiseling, or use the centered hole to draw symmetrical half‑lap joints Fast Mortise & Tenon Layout: Mark along both sides of the bar to transfer perfectly symmetrical lines. The precision‑drilled center hole keeps your pencil dead‑center on the workpiece for efficient, consistent joinery marking Versatile Woodworking Essential: Ideal for woodworkers, carpenters, furniture makers, and DIY hobbyists. Use it for cabinetry, frame construction, and any project that demands accurate center finding and repeatable joint layout Overview Material : Aluminum Brand : LVPETALIZE Color : Red Style : Compact Product Dimensions : 4.3"L x 2.2"W