Key Features & Strengths:

Exceptionally Compact Size: The WL4 series is known for its miniature and low-profile design. Its primary advantage is its extremely small form factor, allowing for installation in tight spaces where standard sensors cannot fit.

Polarization Filter (Key Feature): This model is equipped with a polarization filter. This is a critical feature that allows the sensor to reliably detect shiny, reflective objects (like metallized packaging, glass, or polished metal). The filter ensures the sensor only recognizes the light returned from its specific corner-cube reflector, preventing false signals from glossy target objects.

Retro-Reflective Sensing: Offers a longer sensing range than diffuse sensors while keeping the wiring and installation simple, as only the sensor itself needs to be wired; the reflector is a passive component.

Fixed Cable Connection (3): The "3" in the model number indicates a fixed cable connection (likely a specific length, e.g., 0.3m or 2m, to be confirmed by datasheet), providing a secure and reliable interface.

Robust Housing: Despite its small size, it is built with a robust housing material designed to withstand typical industrial environments.

LED Status Indicator: Features an LED for clear visual confirmation of the switching status, simplifying installation and diagnostics.

Technical Specifications (General):

Sensing Principle: Retro-Reflective with Polarization Filter

Light Source: Visible red light

Sensing Range: Short to medium range (e.g., up to 1.5m or 3m). The "3130" suffix often indicates a 300mm or 3000mm range; the datasheet must be consulted for the exact value.

Operating Voltage: 10...30 V DC

Output Type: The "F" in the model number indicates a complementary output (both NPN and PNP likely available). The exact configuration (NPN or PNP) must be confirmed from the datasheet for the specific model suffix.

Output Function: Light-On or Dark-On operation.

Connection: Fixed cable

Protection Rating: Typically IP67, making it resistant to dust and water ingress.

Typical Applications:
The WL4-3F3130 is designed for space-constrained applications where reliable detection is needed:

Detection inside small machinery and compact automation units

Label presence and package detection on small packaging equipment

PCB and electronic component handling and verification

Door and lid monitoring on consumer product manufacturing equipment

Any application with severe space limitations requiring immunity to shiny objects.