This is the Panasonic LUMIX LEICA DG SUMMILUX 25mm / F1.4 ASPH. Micro Four Thirds lens (product code H-X025):
Note that the Summilux 25/1.4 ASPH lens is designed to be used with the Lumix G Micro System range of interchangeable lens, mirrorless Micro Four Thirds (m4/3) digital cameras. Being a m4/3 lens, the equivalent zoom range in 35mm terms is 50mm.
Sample Photos
A couple of full-sized, full-resolution Panasonic GF3 sample images shot with the Leica DG Summilux 25mm F1.4 and other lenses can be viewed in this official Lumix GF3 gallery.
Accessories and add-ons
The filter thread size on the 25/1.4 is 46mm, which means you’ll want to be looking at purchasing 46mm filters.
Resources
Official Panasonic 25mm f/1.4 page at Panasonic Global.
Related
Panasonic lenses — Main page