Features and Benefits: Performs continuous light-level monitoring for your aquarium Measures actual PAR – the light corals and plants use Prevents burning out corals Includes ASM – the new Advanced Sensors Module PAR sensor hides nicely in aquarium inside Real Reef Rock Fine tune your lighting to your aquariums’s needs Kit Includes: ASM – Advanced Sensors Module NPS – Neptune PAR Sensor Real Reef Rock 6′ AquaBus Cable Requires Apex, Apex Lite, or Apex Jr.