IMPORTANT: 1) This listing is only for 1 (one) arm. The S-20, Model # 4.100 2) Gage, Indicator Holder Base is NOT included! Specs: L: 200mm L1: 120 mm M1: M8 L2: 80 mm M2: M6 Clever central tightening system: -easy positioning -all three joints fixed safely with one handle -maintenance-free, mechanical central tightening system -quick, stepless lock The mid-range Strato model (the Strato S-20) for measurement probes and dial gauges can be used in any type of mechanical system. Pre-tensioning cannot be set. About the Strato Line: The Strato Line is the modern series with red anodized arm sections made of high-quality light alloy. The articulated arms are available in four sizes and can be combined with different bases. About Fisso: The 3D articulated gauging arms from Fisso with a central tightening system stand out due to their high quality and reliability. They are available in several designs: The Strato Line, made of a high-quality red anodized light alloy, is supplied in four sizes. The new ?-Line design allows high-precision measurements. The Classic Line, made of steel with chrome arm sections, is available in six sizes and is quite versatile thanks to a radius of movement ranging from 130 to 630 mm. The simpler Base Line articulated gauging arms are supplied in three sizes. The Fisso articulated arms can be positioned easily and precisely in the desired position. All three joints are fixed with the central tightening knob. The quick lock and the stepless tensioning system assure high ease of use and allow efficient working. The Fisso brand stands for user-friendly, individualized holding systems that meet all customer requirements. Fisso, the well-proven original, ensures high reliability, functional design and is Swiss made. Fisso systems are made of high-quality steel and light alloy. Their solid quality guarantees a long-lasting and maintenance-free service life.