Proximity Sensors are available in models of capacitive sensor and inductive sensor using high-frequency oscillation to detect ferrous and non-ferrous metal objects and in capacitive models to detect non-metal objects. Sensors are available with environment resistance, heat resistance, resistance to chemicals, and resistance to water. Photoelectric Sensors detect photo-optical workpieces. Greegoo provides many varieties of Sensor, including diffuse-reflective, through-beam, retro-reflective, and distance-settable Sensors, as well as Sensors with either built-in or separate amplifiers.