Newly designed smart module for detecting the status of the use of filament. To check the filament is whether run out or not, it automatically pauses the 3D Printer when the filament runs out, so you have a chance to supplement the filament which makes sure you 't print a incomplete printing. Wear- copper sets added in both the inlet and outlet to effectively extend the product life. is a very practical filament detection sensor module, Prefect accessories for 3D printer, making your printing work smooth and relieved. Easy to install, and work steadily and in use. Descriptions: (for board) the green light keeps on when filament is in. If filament is exhausted, the green light goes off. At this moment, board pauses operation and it continue to print after filament is in again. Working principle: The filament detection module uses the level transition detection method. When with filament in, the detection level signal should be high, and when no filament, the filament port level signal goes low. When the system detects a determined transition from high to low level, it regard it as the filament exhausted, then the board executes the pause operation, and after the replacement of the filament, it continue to print. Specification: Color：black material:PC+ABS Applicable filament diameter: 1.75mm/0.069inch Mounting hole size: 3.5mm/0.14inch Mounting hole distance: 20mm/0.79inch Wire length: 1 m/39.4inch Module size: 38 x 30 x 12.7 mm/1.50 x 1.18 x 0.5inch Motherboard wiring: M-sensor port Wire color is random, No specification accepted Package Contents: 4 x Filament Detection Sensor 4 x Cable Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.