The 12 24 nikon, the world's first lens with a smaller image circle, optimized for the sensor format of Nikon Digital SLRs such as the D100, the D1X, the D1H and the D1.

Nikon 12 24mm features

12-24mm ultra-wide angle G type zoom lens equivalent to 18-36mm in 135 format
Three aspherical lens elements minimize distortion, especially at the periphery, for superior optical performance.
Lightweight design that fits comfortably on compact digital SLR bodies such as the D100.
Not recommended for use on 135 format cameras.

The Nikon 12-24mm includes:
Lens Cap LF-1 and Lens Hood HB-23