Cogged V-Belt; Type BX, Classical; Outside Circumference 59 Inch; Inside Length 56 Inch; Top Width 0.66 Inch; Thickness 0.43 Inch; Material Pre-Stretched Polyester; Applicable Standard RMA, ISO 9001; Pitch Diameter 4 Inch; Angle 40 Degree; Outside Diameter 4.35 Inch. BESTORQ® single, raw edge notched V-belts give premium belt performance. The belts are constructed of highly engineered, high performance components. The components are made using the latest in belt technology available on a global basis. The “X” in the part number refers to higher load ratings than standard wrapped belts.