VEXpro 5mn High Torque Drive (HTD) Profile Timing Belts 9mm Wide - VEXpro 217-3455, A 9mm wide timing belt perfect for FIRST ® Robotics Competition applications.Synchronous timing belts require no tension adjustments, are lighter, and have a higher level of efficiency than chain. Their 5mm HTD deep tooth profile allows them to better handle high reversing loads, such as those found in a FIRST ® Robotics Competition drive-train.VEXpro belts are fabricated using industry leading timing belt methods. Their neoprene body insulates against grease or other wear & tear, and fibreglass tensile cords provide increased strength, flex life, and resistance to elongation. VEXpro 217-3455 Timing Belt HTD 5mm 70T 9mm Wide