Olympus ED 12-50mm f3.5-6.3 EZ is an Auto Focus (AF) Standard Zoom lens with FourThirds max sensor coverage. When mounted on a FourThirds sensor camera, it will give you an FF equivalent focal range of 24 - 100mm. With a max aperture of f3.5 at 12mm, we can not consider this lens fast on wide end, and it is slow at the tele end with its max aperture of f6.3.
Olympus ED 12-50mm f3.5-6.3 EZ is weather sealed which makes it an ideal lens for outdoor use, especially when coupled with a weather sealed camera body.