Product Name: Proximity Switch Sensor; Model: SN04-N; Type: DC 3-wire NPN NO; Sensor Type: Inductive Proximity Sensor; Output: Switching Transducer; Sensing Distance: 4mm; Operating Voltage: 10-30V DC; Maximum Response Frequency: 500Hz; Indicator: Red LED; Dimensions: 18 x 18 x 36mm (0.7 x 0.7 x 1.4 inches); Cable Length: 135cm (53 inches); Mounting Hole Size: 0.9 x 0.4cm (0.35 x 0.2 inches); Housing Material: Metal; Net Weight: 48g; Color: Black, Green; Features: Over-current and short circuit protection, LED status indicator for easy identification. This proximity sensor switch is suitable for detecting objects based on size and speed, and can be used in applications such as frequency counting, pulse generation, liquid level control, and automated process control. Package Includes: 1 x Proximity Sensor Switch, 4 x Mounting Screws. Note: Actual product color may vary slightly due to lighting and display settings. Measurement tolerances may vary by ±1-3cm.