Extending the effective focal length of select Tamron lenses, this Canon EF-mount Teleconverter 2.0x enables you to get even more reach out of your telephoto lenses. The dedicated design retains communication between the lens and Canon EF-mount cameras, including auto-exposure metering and Vibration Compensation image stabilization, and both one low dispersion element and a BBAR coating has also been incorporated to maintain image quality. Additionally, this teleconverter also features a dust- and moisture-resistant construction, matching the lens, to benefit working in harsh environmental conditions.