The small red light spot provides more accurate detection of objects. It has a BGS function and is not affected by background objects. The ultra small size is only W11xH31xD20mm. Small size can be installed in narrow spaces. Equipped with sensitivity adjustment and action indicator light. High quality detection capability and high detection sensitivity. It has short-circuit protection and power polarity protection. The response time for action reset is 1ms. Excellent anti-interference function can be installed tightly in two sets.