420mm-800mm f8.3-f16 Manual Telephoto Long Lens T Mount for DSLR Features: Connect the camera and lens with the ring, set the camera panel on M manual No show of aperture unless from shutter speed or ISO to change the exposure, some cameras can achieve automatic exposure The tripod is necessary (not included), the lens has a tripod ring to directly connect the tripod, pay attention not to connect the tripod with the camera Manual adjustment, full metal structure, optical glass multi-layer MC coating It possesses 420mm-480mm super long variable focal length ideal to watch birds and wildlife. It offers a T mount accessible to various rings and suitable to various DSLRs. Instructions: Manual lens with no electric button included. It can be connected on various DSLRs with different rings, supporting silent frame and ILDCs. Specifications: Lens construction: 4 elements in 2 groups Aperture: F8.3 to F16 Filter diameter: 67mm Shortest focusing length: 1.5m Lens length: 298mm Weight: 650g Color: Black Material: aluminum magnesium alloy, optical glass