This is the wool sleep sack I have just finished:
It was constructed from two (very large) reclaimed sweaters. The outer layer is charcoal gray with cream, gray, beige, and rust stripes. It is a very soft blend of 85% wool, 10% nylon, and 5% silk. The back is solid charcoal (no stripes). The lining is soft 100% lambswool in beige color. The black overall straps are also 100% wool, cut from some fabric that I reclaimed from a suit jacket. Oh, and the snaps glow in the dark!
The whole sleep sack measures 24 inches (about 60 cm) long from the top edge (not including the straps) and about 9 inches (23 cm) across the top edge. The straps have three snap settings, making them adjustable as your baby grows.