SRD:Stone of Alarm

Stone of Alarm: This stone cube, when given the command word, affixes itself to any object. If that object is touched thereafter by anyone who does not first speak that same command word, the stone emits a piercing screech for 1 hour that can be heard up to a quarter-mile away (assuming no intervening barriers).

Faint abjuration; CL 3rd; Craft Wondrous Item, alarm; Price 2,700 gp;Weight 2 lb.