SICK WTB2S-2P3151 Photoelectric sensors. SICK WTB2S-2P3151 is a photoelectric sensors in the W2 family. SICK identifies this exact configuration as manufacturer article 1067502. The official technical record specifies Functional principle: Photoelectric proximity sensor; Functional principle detail: Background suppression; Dimensions (W x H x D): 7.7 mm x 27.5 mm x 13.5 mm; Housing design (light emission): Rectangular; Sensing range max.: 1 mm ... 150 mm 1); Sensing range: 18 mm ... 110 mm 1). The linked SICK data sheet is specific to WTB2S-2P3151.