The BOLT-NL can measure fiber links of up to 25 kilometers, and is accurate to within 2.5 meters. Each unit comes with a protective rubber boot, carrying strap, 9-volt battery, and CD-ROM with operations manual.
VOLT functions as any good quality Visual Fault Locator (VFL). However, with the same price range as other VFL's VOLT has the added benefit of doubling as a LOOPING length tester! Many cabling warranties and bids are requiring meter based length tests