XR: Extra Refractive-Index glass (allows smaller size)

Di II: Only works on 1.6x and DX cameras, won't work on 1.3x or 35mm or full-frame cameras.

LD: Low dispersion

IF: Internal focusing. Nothing moves, except the focus ring, as focused.

Aspherical: Specially curved lens elements.

Aperture range: f/2.8-32

Fully serviced

90 day warranty