Thiết bị test line điện thoại Proskit NT-6006

This tool is for testing the condition of dual telephone line jacks. Multicolor LED indicator light alerts to okay line, reversed line, AC Voltage present and dead line. Fits in shirt pocket.
Dual telephone line tester that troubleshoots common problem conditions with standard single or dual-line telephone hook-ups.
Compact unit easily plugs into any single or dual-line telephone jack.
Tests for three wiring conditions: correct, reversed and AC volt age presence.