Based on a compact and simple design, the ESL series torque limiters from R+W offer accurate performance at a reasonable cost. Unlike traditional ball-detent torque limiters, the ESL spring loads two series of ball bearings against one another to create a rolling effect at overload. This reduces wear, and at the same time it allows for the clutching interface to serve as the bearing support during overload disengagements; saving space and cost. Since this torque limiter uses specially developed, "digressive spring characteristic," sensitivity to overload and accuracy of disengagement torque are not compromised. This means that disengagement takes place within 3 milliseconds of overload, and at a value within +/-5% of the disengagement torque setting. The basic design mounts by means of a keyway and set screw, though customized mounting attachments are also available.