Sure-Flex Shaft Coupling - With well over 35 years of product knowledge combined with a large stock of Sure-Flex Couplings and Sleeves provides a great basic shaft coupling solution. Mix that with knowledgeable staff who are always available, and you have a great combination. The basic coupling uses two cast hubs available pre-bored or pilot bored and a proven centre element produced from a elastic polymer, to compensate for arduous shaft misalignments. The proven product delivers reliable torque transmission whilst simultaneously dealing with shock and vibration.