Blue Ring Tester Kit The perfect companion for the Blue ESR! This ring tester is an inexpensive and effective way to test any high Q inductive component. It is especially useful for doing a quick check on flyback transformers, line output transformers and other high frequency inductive components like deflection yoke windings and SMPS transformers. Tests in circuit, & test leads are non-polarized Easy-to-read, high brightness red, yellow and green LEDs display the Q of the device being tested. Simple operation for fast easy diagnosis of faulty inductive components. New Improved design increases sensitivity for low impedance components such as SMPS transformers and deflection yokes. Supplied with standard alligator clips. Accessories and options include Blue Silicone Leads, Stand and Heavy Duty Croc Clips.