Baumer FZAM 18N1155 Photoelectric Diffuse Sensor with Intensity Difference, Ø18 x 50mm, 10-30VDC, 20-150mm Sensing Distance Tw, 30-280mm Sensing Distance Tw with Doubling Lens, 200mA, NPN, Light Operate, Nickel Plated Brass Housing, Polycarbonate Front (Optics $199.00 Select