The Klein Tools Replacement Lead Kit for TDR Cable Length Meter is comprised of 5 lead types for use with the TDR Cable Length Meter (Cat. No. 501-915). Designed to measure cable length, calibrate Velocity of Propagation (VoP) values, find distance to faults, with built-in tone generation for cable tracing (tracing proble Cat. No. VDV500-123 sold separately) for a wide variety of cable types.