BESTORQ X3 fabric wrapped V-belts bring in a new generation of wrapped V-belt performance; These belts are constructed of highly engineered, high-performance components that are manufactured using the latest in belt technology available on a global basis They are specially designed to be low maintenance and are proven to be extra durable for belt life that will outlast the competition; Reduced maintenance downtime and increased machine uptime means you save time and money The helically wound tensile cords are created of a pre-stretched polyester material specially engineered, twisted, then set by both heat and chemical means; Testing has proven that the tensile decay properties of BESTORQ Cord are truly World Class X3 v-belts are amazingly uniform and smooth running; With excellent adhesion between components and low stretch tensile cords, they have very low elongation and will not require any rechecks or retensioning if installed at the correct recommended tension The BESTORQ A81 or 4L830 v-belt has a 83" outside circumference, 81" inside circumference, .51" width, and a .34" height; See images for cross section schematic