This sensor is known variously as the Keyes, KeyesIR or Keyestudio KY-032. It is the the functional equivalent of the IrBeady IR-08H, also known as the AD-032. The sensor uses a four pin connector, The pins are labeled: EN (Enable), out (Output), + (Power) and GND (Ground). There are also two potentiometers on the board and one jumper (see picture). Output signal: TTL level LOW level if obstacle detected HIGH if no obstacle detected Adjustment: two single-turn variable resistors Effective angle: ?35? Size: 28mm ? 23mm Weight: 9g One of the potentiometers on the board (R6) is used to fine tune the signal to exactly 38kHz. The other (R5) adjusts the duty cycle of the signal, which controls the brightness of the IR LED. Both adjustments together effect the sensitivity or range of the device. Proper adjustment of R6 requires an oscilloscope or a frequency counter. Otherwise it can be left centered or as it came from the manufacturer. The receiver module also includes an AGC (Automatic Gain Control) that will suppress a continuous signal of any frequency, including 38kHz (see excerpt from data sheet, below). Therefore, it is absolutley necessary to use the ‘EN’ or ‘Enable’ pin for proper operation of the device. If the Enable function is used correctly, the device will achieve its maximum sensitivity. On most versions of this device, the Infra Red (IR) LED is already covered with a small piece of black shrink tubing; but I find that additional optical shielding is required. A small cardboard tube commonly used as packing material will work satisfactorily, as will a variety of other materials.