Horn of Blasting

This horn appears robe a normal trumpet. It can be sounded as a normal horn, but if the command word is spoken and the instrument is then played, it has the following effects, both of which happen at once:

• A 100-foot cone of sound issues forth from the horn. All within this area must make a Fortitude saving throw (DC 16). Those who succeed are stunned for 1 round and deafened for 2 rounds. Those failing the saving throw take 1d10 points of damage, are stunned for 2 rounds, and are deafened for 4 rounds.
• An ultrasonic wave 1 foot wide and 100 feet long issues from the horn. The wave weakens such materials as metal, stone, and wood. This effect deals 1d10 points of damage to objects within the area, ignoring their hardness.

If a horn of blasting is used magically more than once in a given day there is a 10% cumulative chance with each extra use that it explodes and deals 5d10 points of damage to the person sounding it.
CL 7th; Craft Wondrous Item, shout; Market Price: 12,000 gp; Weight: 1 lb.
Source: Dungeon Master's Guide v.3.5