SICK WTB4FP-213111A0ZZZ Photoelectric sensors. SICK WTB4FP-213111A0ZZZ is a photoelectric sensors in the W4 family. SICK identifies this exact configuration as manufacturer article 1125739. The official technical record specifies Functional principle: Photoelectric proximity sensor; Functional principle detail: Background suppression, MultiPulse; Sensing range min.: 28 mm; Sensing range max.: 165 mm; Reference object: Object with 90% remission factor (complies with standard white according to DIN 5033); Minimum distance between set sensing range and background (black 6% / white 90%): 23 mm, at a distance of 165 mm. The linked SICK data sheet is specific to WTB4FP-213111A0ZZZ.