Features: The Cassettes tape measuring instrument can accurately measure the height of the magnetic tape guide, the travel of the magnetic head, and the zeniths of the magnetic head. Our guide gauge is craft from aluminum alloy, with Highly strength, wear resistance, corrosion resistance, and durability. The cartridges type scale is easy installation. Fashionable appearance, light weight, and accurate measurement. Suitable for various types of reel to reel tape recorders. Specifications: Material: Metal Type: with 1 Check Bar, with 2 Check Bar, with 3 Check Bar (optional) Guide Gauge: about 10x6.3cm/3.94x2.48inch Check Bar: about 3.7x0.6cm/1.46x0.24inch Package Includes: 1x Tape Recorders Head & Guide Gauge with 1pc/2pcs/3pcs Check Bar(optional) note: Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.