SICK GTB6-P3211 Photoelectric sensors. SICK GTB6-P3211 is a photoelectric sensors in the G6 family. SICK identifies this exact configuration as manufacturer article 1084646. The official technical record specifies Functional principle: Photoelectric proximity sensor; Functional principle detail: Background suppression; Sensing range max.: 5 mm ... 250 mm 1); Sensing range: 35 mm ... 140 mm; Light source: PinPoint LED 2); Type of light: Visible red light. The linked SICK data sheet is specific to GTB6-P3211.