Sensor, I.D. T4607100, embeddable, 4mm distance, 3-wire, threaded 12mm.     
Input 10-30 VDC, output NPN,  Max. load 200ma,     
With M12 4-pin Eurofast connector. - Actual picture of item.     
The item is used - like NEW - tested - 60 day Warranty.     
For additional accessories see:     
http://www.kkdepot.com/category.asp?cat=38    
Price $29.00 ea. (5 available)