Bellows

The Bellows are a common item on the earlier levels in Bad Piggies. It's first location is in the second level of the first episode, Ground Hog Day. It can be found on lots of levels.

Use
Bellows can give contraptions a little push, depending on what direction of the contraption it is placed on. It works on left, and right, and it is pretty useless in the up and down department.