This 300mm F6.3 lens is computer-designed using a combination of lenticular light refraction and reflection optics--the same physics used in many professional telescopes. 

Features: 
300mm f/6.3 Studio Series Telephoto Mirror Lens. 
Multi Coated low-dispersion glass， anti-reflection coating. 
A Multi-coated low-dispersion glass capable of producing sharp， high definition images. 
Suit for Nikon Mirrorless Camera. 
This gives you very sharp picture quality with less color aberration， which is considered the most harmful factor in the field of telephoto photography. 

Specifications: 
Focal length: 300mm 
Lens Construction: 7 Elements in 4 Groups 
Angle of View: 5 degrees diagonal 
Aperture Range: F6.3 
Minimum Focusing Distance: 0.8m / 31.5in 
Package size: 14.5 * 10.5 * 11cm / 5.7 * 4.1 * 4.3in 
Package weight: 440g / 15.54oz 

Package List: 
1 * Lens 
1 * Front Lens Cap 
1 * Rear Lens Cap 
1 * Hood 
1 * Lens Bag