SICK ZLD18-9AB4B2 Photoelectric sensors. SICK ZLD18-9AB4B2 is a photoelectric sensors in the Z18 Simple Sense family. SICK identifies this exact configuration as manufacturer article 1095731. The official technical record specifies Functional principle: Photoelectric retro-reflective sensor; Functional principle detail: With minimum distance to reflector (dual lens system); Dimensions (W x H x D): 14.4 mm x 20.5 mm x 23 mm; Housing design (light emission): Hybrid; Thread diameter (housing): M18; Mounting system type: M18, head/dovetail mounting with base. The linked SICK data sheet is specific to ZLD18-9AB4B2.