SICK VTF18-4N1240 Photoelectric proximity sensor. SICK VTF18-4N1240 is a archive in the V18 family. SICK identifies this exact configuration as manufacturer article 6012822. The official technical record specifies Functional principle: Photoelectric proximity sensor; Functional principle detail: Background suppression; Dimensions (W x H x D): 18 mm x 18 mm x 78 mm; Housing design (light emission): Cylindrical; Housing length: 78 mm; Thread diameter (housing): M18 x 1. The linked SICK data sheet is specific to VTF18-4N1240.