Taiwan polar sun 139B 139B instrument polarity tester (Origin: Taiwan Sunshine) Product description: from environmental noise, immediately determine the polarity of any type of speakers, headphones, suitable for use in the production line. Connection with three different instruments (152A, 7117C, and 7116C), only one person can operate, saving labor, time-saving. Easy to learn, easy to use, excellent reliability. Polarity: a positive polarity: the green LED lights and beep b negative: red LED lights buzzer does not sound technical parameters: Measuring the pulse width of about 0.4ms pulse amplitude measurements maximum sensitivity ≤10Vp-p ≤ measuring speed of about 0.2 seconds 25cm Specifications Dimensions (MM): 85 (H) × 205 (W) × 280 (L) Weight: 2.3KG 139A (with control) - that can be online with three different instruments (152A, 7117C and 7116C) use; 139B (without control) - and that is not online with three different instruments (152A, 7117C, and 7116C) use; 139C (dual channel) - that there are two channel microphone jack, which can use two microphones, but not with three different instruments online (152A, 7117C, and 7116C) Use