The Seco 8.5-Foot Quick Change TLV Carbon Fiber Prism Pole 5507-17 is made of solid black, wear-resistant carbon fiber. Its inner pole features dual graduations in feet, tenths, and hundredths of a foot and centimeters while its outer pole has none. When the inner pole is fully extended, the prism pole measures 8.53 feet; and, when it is fully collapsed, the prism pole measures 4.97 feet. A soft, rubber knob lock tightens or loosens easily to secure the two sections. The included adapter gives this prism pole a 5/8 x 11-inch top thread which allows surveying professionals to mount a wide variety of prism assemblies. Additionally, a built-in 40-minute level vial makes it possible to keep your prism pole level at all times.