This instructional video differentiates two types of spearguns. The pneumatic spearguns have no bands; instead, the spear is powered by air. On the other hand, a banded spear gun will have usually one to three bands that are pulled back and put into notches on the spear before you are able to shoot the speargun. Both types of guns are great and either one can be used while scuba diving or snorkeling. Each gun has it´s advantages, so it is up to you to decide which gun will work for you the best.