30mW 905nm IR Infrared Laser Diode Dot Module w/ TTL 0-15KHZ Focusable UnitDC5V. 1pc Focusable 30mW 905nm IR Infrared Laser Diode Dot Module w/ TTL 0-15KHZDC5V. 1.Three-wire input, the red line is positive, black line is negative, TTL signal yellow line is positive,If you only connect its black wire and red wire, the laser would not work, you also need to connect its yellow wire (TTL+) to 5v+.
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