Alat test speaker mobil phasemeter test polarity

Black Speaker Polarity Tester PH Phase Meter Phasemeter for Auto Car Product Name: PH Phase Meter; Material: Plastic,Metal Package Content: 1 x PH Phase Meter Powered By: 1 x 9V 6F22 Batterynot included Perfect for safely troubleshooting and testing audio systems. This phase meter can test all speakers of all car, su as small treble, door speakers, subwoofer, etc.