BLTouch is a type of semiconductor hall sensor and is an electronic component for 3D Printers. BLTouch is an auto-leveling sensor for 3D Printers that can precisely measure the tilt of the bed . It could work with any kinds of bed materials, such as glasses, woods, metals, and so on. BLTouch is fulfilled with simple structure and high precision by using progressively designed solenoid and hall sensors. It for user convenience and enjoyable printing by adding many smart functions, such as self-test, alarm, alarm release & Contact Switch mode, Blue LED for servo signal indicating, and Z-probe() Testing. Application Series: -10 Series: -3, -3X, -5, -5 Pro, -3 Pro Notice: to 3 V2 The main functions and controls of BLTouch are the same as the usual auto bed leveling sensor, which consists of an RC servo and microswitch. Thus, BLTouch can be applied on almost every board. Self-test: The push pin operates two times in a test when the power is on. Alarm:The LED light blinks if a problem was found on a self-test or during operation Wiring defect indicator:Blue and Red LED for indicating wiring defects. Easy to Use: This auto bed leveling sensor makes it easier to level the hotbed, which can precisely measure the tilt of the Bed . Bed leveling is not a problem anymore. Intelligence self - check and alarm: The function of auto leveling is adopted to easier to use and to increase the success rate of. Colour: black Material: plastic Package Contents: 1 * 3D Touch-sensor 1 * SD card converter (for -3 V4.2.7 version mute motherboard) 1 * Connecting line 1 * Bracket 2 * Cable tie 1 * Wrench 4 * Screw 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.