-One I/O for control (PWM or Software PWM)
-One I/O for Zmin(Z Probe)
-GND and +5V power

Notes:

-Additional power supply can be needed in case which your board does not supply enough amperage.
-Electronic devices can be damaged or even destroyed if connected to the wrong side polarity. [wrong terminal connect to 5V(+) and GND(-)]
-Install BLTouch as far as it possible from magnetic, motor, fan etc.
-The action as pulling/pushing hard the push-pin can make the BLTouch damaged and less accurate.
-Fix push-pin with locking paint after reassembling or adjusting core.
-Please do not change the position of the hex screw(core).
-Do not separate or deform elastic material attached on the push-pin.
-The action(Pull or push push-pin hard) makes damage and lowers the accuracy of sensor

Package Included:

1 X Sensor
1 X 3Pin Straight Pin
1 X 2Pin Straight Pin
2 X Screw & Nut & Washer
2 X Dupont Housing Shell 3Pin
2 X Dupont Housing Shell 2Pin
10X Dupont Terminal
1 X 10KΩ 1/8W Resistor for Smoothieboard

Here are more info. for your reference:

1. More product info.
2. Common probe adaptation model 3D STL
3. Video info.
4. User maunal