Shredders are handheld energy weapons used by the Andalites. Due to the devotion Andalites show to their tail blades, the shredders fire their beams from tails perched on Andalite ships. The Yeerks created a more brutal variant of these called Dracon beams. The two weapons have been compared to the phasers from Star Trek.
In The Andalite Chronicles, Elfangor said Shredders have seven different power settings. Level one delivers a mild, light charge, enough to stun an average creature for a few seconds, while level seven is powerful enough to blast a hole through ten feet of solid alloy. However, that configuration was from many years ago in Andalite history, and it was referring to a Yeerk model, so it is unknown how much Andalite technology, having advanced over that period of time, differs from this old Yeerk model.
The shredders equipped on the andalite dome ships are far more powerful than any hand model. Ax has stated that the energy and heat released from a single fill-powered blast are so great that if aimed at a planet it could set the entire atmosphere ablaze and render its surface little more than a charred crisp.