While other guns on the surface use gunpowder or another type of propellant to make the projectile move forward, spear guns work much more like a slingshot.
To shoot the spear through the water, the spear gun uses a thick rubber band that stores all of the tension until the hunter pulls the trigger and releases the bands. Speargun band is specialized, and you need to buy the special tubing for it to work with your spear gun.

Speargun bands are available in one piece, and then it is up to you to cut it down to size to meet the specifications of your spear gun.
It might seem complicated, but there are tons of guides and online calculators to determine the length of your spear gun band. Check them out and shop our selection of premium spear gun bands at Adventure At Nature.