SICK WTB4FT-31311120ZZZ Photoelectric sensors. SICK WTB4FT-31311120ZZZ is a photoelectric sensors in the W4 family. SICK identifies this exact configuration as manufacturer article 1113180. The official technical record specifies Functional principle: Photoelectric proximity sensor; Functional principle detail: Background suppression, DoubleLine; Sensing range min.: 7 mm; Sensing range max.: 120 mm; Adjustable switching threshold for background suppression: 15 mm ... 120 mm; Reference object: Object with 90% remission factor (complies with standard white according to DIN 5033). The linked SICK data sheet is specific to WTB4FT-31311120ZZZ.