The Pen type VFL's extremely high efficiency guarantees prolonged operation with two standard AAA alkaline batteries, typically providing 50 hours of uninterrupted operation. Priced to accommodate the tightest budgets, the VFL-x Pocket Pal is a truly affordable way to locate faults in OTDR dead zones. Its effectiveness justifies purchasing one for just about every fiber technician. New technology with AL composite material makes the PEN lighter, while the imported Mitsubishi LD Laser ensures more gathered light signals and less attenuation.