The Zipper shoots a ball of energy that sticks to the ground upon impact, repeatedly going the same distance to the right and the left of where you hit, dealing 4 damage every time it touches an enemy. The Zipper will always deal the same amount of damage no matter if the enemy stands to the left, to the right or directly where you hit. Visually the weapon indicates that a perfect hit would increase damage even though it doesn't. With a puny 32 damage against a single target it is better to wait until multiple enemies are grouped up since a guaranteed 32 damage can be dealt to each target, as long as they are within the range of the left-right path.