Nice prox switch that sold for about $56 from Newark electronics. Why not buy mine for so much cheaper?! Plus, it's discontinued so if you want a drop-in replacement this is your sensor.

 Order Code: BES001ZM
Inductive Proximity Sensor, Cylindrical, BES Series, M12x1-male, 4-pin, A-Coded, Flush, 4 mm, PNP, 12 V to 30 V, Connector

The BES M12MI-PSC40B-S04G-M01 is a Quasi flush mounted inductive Proximity Switch with nickel-plated brass body and M12 connector 4 wire connection. The sensor is functional again after the overload has been eliminated.
  • IP68 Protection rating
  • -25 to 70°C Operating temperature range

Dimension
Ø 12 x 65 mm
Style Housing
M12x1
Installation
for flush mounting
Range
4 mm
Switching output
PNP normally open (NO)
Switching frequency
1000 Hz
Housing material
Brass, Nickel-free coated
Material sensing surface
LCP
Connection
Connector, M12x1-Male, 4-pin
Operating voltage Ub
10...30 VDC
Ambient temperature
-25...70 °C
IP rating
IP68
Approval/Conformity
CE
cULus
EAC

  Load capacitance max. at Ue 0.5 µF
 Min. operating current Im 0 mA
 No-load current Io max., damped 12 mA
 No-load current Io max., undamped 5 mA
 Operating voltage Ub 10...30 VDC
 Output resistance Ra 33.0 kOhm + D
 Protection class II
 Rated insulation voltage Ui 250 V AC
 Rated operating current Ie 200 mA
 Rated operating voltage Ue DC 24 V
 Rated short circuit current 100 A
 Ready delay tv max. 10 ms
 Residual current Ir max. 10 µA
 Ripple max. (% of Ue) 15 %
 Switching frequency 1000 Hz
 Voltage drop static max. 2.5 V

Dimension Ø 12 x 65 mm
 Installation for flush mounting
 Size M12x1

Ambient temperature-25...70 °C
 Contamination scale 3
 IP rating IP68

 Range/Distance
 Assured operating distance Sa 3.2 mm
 Hysteresis H max. (% of Sr) 15.0 %
 Rated operating distance Sn 4 mm
 Real switching distance sr 4 mm
 Repeat accuracy max. (% of Sr) 5.0 %
 Switching distance marking ■■
 Temperature drift max. (% of Sr) 10 %
 Tolerance Sr ±10 %