OWL KF7VMS - Fiber OWL 7V / WaveSource Pro Quad Compact size Color LCD display Multiple versatile test modes Comprehensive OWLView Tri-report The Fiber OWL 7 series is a test kit that ideal for the fiber optic professional who requires standards-based certification of fiber links, including TIA-568, ISO 11801, various Ethernet standards, among others. The Fiber OWL 7 can also be configured with custom standards to meet the needs of various fiber optic applications. Attenuation (Optical Loss) Measurements. After a fiber cable has been installed and terminated, optical loss measurements can be used to determine if the fiber is installed according to standards and specifications. A comparison between the actual power measurement and the reference value determines how much optical power is lost through the link.