B121 Classical V-Belt (21/32" X 124")One New Aftermarket Replacement Classical V Belt (B121) 21 32" x 124" Outside Circumference The B121 is a B section classical wrapped V belt used across a wide range of agricultural, lawn and garden, and industrial power transmission applications. The trapezoidal profile wedges into sheave grooves to multiply friction on the pulley sidewalls, delivering reliable torque transfer on drive systems throughout tractors, mowers, combines, and general