The Graham Field 3406 (Grafco/Labtron) is a heavy-duty laboratory cleaning tool specifically designed for deep-vessel sanitation. This professional bottle brush features high-quality white nylon bristles that are chemical-resistant and maintain their shape after rigorous scrubbing. The bristles are securely mounted on a sturdy, twisted galvanized wire handle that provides the necessary tension to remove stubborn residue from the internal walls of bottles, flasks, and large test tubes. With an 11-inch total length and a generous bristle diameter, it is an essential maintenance tool for hospitals, research labs, and clinical environments.