V-Belt M Section M33 / Z33 Belts are measured on the internal circumference Sizing: Width: (inches) 3/8" (mm): 9.5mm Inside circumference (inches) 33" (mm): 838.2mm Outside circumference (inches) 34" (mm): 863.6mm Please check your sizing as some Manufacturers measure on the external circumference. The difference between the internal and external circumference is 1" High quality aftermarket replacement belt Certified in manufacture ISO/TS16949:2016 and ISO 14001 OHSAS 18001 These belts meet the 'essential' Health and Safety norms for its entire range of fire-resistant, anti-static belts All parts need to be fitted by a licensed technician. Please note: Due to supply issues sometimes this belt is unavailable in PIX brand and have been substituted. PIX measure on the internal circumference as per listing Some brands eg. Allwyn measure on the external circumference