Vibration CompensationVC (Vibration Compensation) is Tamron’s proprietary image stabilization mechanism which reduces the effects of camera shake to deliver sharp images in low light and at slower shutter speeds. It is a newly developed three coil system that employs a lighter moving coil mechanism which contributes to its improved performance and overall compact design.Ultrasonic MotorUSD (Ultrasonic Silent Drive) Motor is the power for a fast and quiet autofocus drive that works in harmony with continuous manual focus mechanism.XLD and LD OpticsOne special XLD (Extra Low Dispersion) and four LD (Low Dispersion) elements minimize chromatic aberrations.Multi-layer CoatingTamron’s advanced multi-layer coating technology dramatically improves lens performance by reducing flare and ghosting for crisper, clearer images.Moisture ResistantMoisture-resistant construction helps prevent moisture from penetrating the lens.Compact DesignImprovements in the lens’ Vibration Compensation system and a new overall design keep this 70-200mm lens slightly smaller than others in its class. Diameter is 3.37″(85.8mm) and length is 7.4″ (188 mm).Tripod Collar and Lens HoodA rotatable, removable tripod collar comes with this lens and allows for stable, balanced tripod mounting, and a matched petal-type lens hood is also included.