What are the knob adjustments on the side for?
Description in the link posted above...
DH-PFM511 series of fill light for the intelligent fill light, according to different environments to adjust the lamp brightness and light threshold. Products selected imported high-power LED chip light source, after accurate optical design, so that light intensity evenly distributed to achieve the overall highlight effect for video surveillance, vehicle pedestrian and other target detection and capture to provide professional fill light. Products can be widely used in parking, toll stations, entrances, security card mouth, road monitoring and other systems
Product Features:
Support a variety of installation methods, such as standing, wall, flat mounted
- IP66 protection class
- Aluminum die-cast housing
- Support LED light brightness adjustable
- Support light threshold adjustable
- Support 220V power supply
- The use of integrated light lens